Actually they have been at a rip-roaring pace, getting faster an faster, there two reasons why this isn't apparent to players:
First. The tools to build the game are what consume the largest amount of time money and resources, these tools are the cutting edge and will allow content creation at speeds never seen before and in ways never dreamt of before by any other game developer (believe it or not, it doesn't matter). Stanton was chosen as a system to begin with because it has variety, the tools to create it can now create other planetary systems much more quickly.
Stanton is the first and only system that will be worked on iteratively, the other systems will arrive more or less complete.
Second. What we see in the game now is merely a test-bed and major features are either being held back or are not functioning as intended because the server architecture can't handle more than there is right now. The work that they have done on the AI NPC's is phenomenal, but you can't see it in the game yet because the servers can't handle all the NPC's and the object container streaming together.
Only those who can think in terms of Jesus Patches and finished releases worry about what is happening with Star Citizen, the rest of us know it is not a miracle tech patch that will change things, it is block by block by block being built steadily, but faster and faster as tools and skills improve.
When they have a system that will allow parts of the Stanton system to be held on meshed servers then things will improve markedly. However meshing depends upon the backend services and persistence being in place, the new name they have for this is the Entity Graph (formerly iCache, pCache, Global Persistence), they have been steadily working on those and if you go to the SC Youtube channel and watch Tony Zurovec's presentation you'll understand more what the eventual goal is meant to be.
What's the blow your mind experience of Star Citizen compared to other games? Go away for a few days, come back tomorrow and everything could look and feel completely different. No other game studio would even think to do such a thing in a non-narrative multiplayer game.
People ask what is the 'amazing new thing', unique selling point of Star Citizen? They laugh when we say, it will be a living breathing universe that would go on whether players are there to see it or not - players are the minority, you are going to have a level of agency and permanency you've never seen in a multiplayer game before. You will find yourself one day looking at a calendar of events, or posters around the verse suddenly appearing and you'll realise, this universe just keeps going on and on and on like none we've ever seen before, and there are just so many places and things to do you'll never get around all of them.
But the negativity is because people only see what is there now, this is nowhere near all the work that has been done - not even close, and of course there is also Squadron 42 Chapter One. This is not a Call of Duty first person game with multiplayer tacked on, both games will be intimately connected.
The thing that is going to blow people away is not the pretty sunsets, detailed planets and clouds, flora and fauna even though they are pretty spectacular - it is the population of characters that you will see and meet. The knock your socks off unique selling point of Star Citizen is not a competition with Unreal Engine 5 for eye-popping eye-candy, it is the 'would never be attempted' level of realism of the characters in the UEE universe and beyond, communities and events that players will immerse themselves in. The Murray Cup racing league takes place in the universe, it's not just Arena Commander.
The reason you have probably lost your enthusiasm is because you likely haven't really looked into the magnitude of what is to come. When you see people compare Star Citizen to another other game, you have to realise - Yeah.. but all the other games are in there too! Just about anything you can do in a game (of just about any type) you will be able to do in Star Citizen.
The places are not the big deal, the ships are not the big deal, the living breathing 'going on around you everywhere universe be there or miss it' is the blow your mind event to come. There are annual events and one off events even now and they are just the tasters for what is to come.
People watch the videos that CIG make and insist they are just promo videos usually for events and ships sales - they aren't just promo's, they are telling of what life is going to be like in the verse. The biggest most immersive sandbox - first person universe - MMO ever made.
The major technical challenge facing CIG is not server meshing - it's been done by other before, or full persistence, or even building planets and locations fast enough - they are doing that ever more efficiently but there is no point in dropping all of that into the game for sight-seeing rubber-neckers only, just to silence the naysayers. The real challenge is going to be how to populate that massive universe and they have things up their sleeve few barely realise yet (change the paradigm next level poo poo!) and Tony Zurovec has only scratched the surface of showing what he is planning.
No other game has such a massive population and each one of those characters is unique and mortal, they will live and die, they will have jobs, they will have friends and favourite places to go and dreams - you will be able to individually recognise all NPC's by their faces. NPC's will not be fixed in place like Heimskr's they can move and migrate around the universe just like players (no other game studio has even thought of such a thing because the cost by traditional methods would be astronomical and it's too easy to fake it). The variety we will see is just staggering, but even more staggering is the capacity to change.
This post will get downvoted extremely fast in all likelihood (all I need to do is post a picture of kittens in r/awww if I wanted to farm karma or avoid loss of karma) because those who can't fathom such a thing and hate the idea of this project succeeding will do it, what they hate is the idea that anyone else coming along might dream bigger than they can, even though they have nothing to offer in it's place.
When you go into the game try to realise it was dreamers who built this universe - we came together to do better than the biggest and the best, not investors or cynics, and it's the dreamers who are still building it and will continue to build it for many more years to come, how many other games do you know will expand year after year after year without let up - and you don't get any extra charge for it? When the game is 'finished' as everyone insists it should be following the standard game development design that they can only envision is when the dreams die, we've seen that with Cyberpunk2077 and even Elite Dangerous Odyssey.
We didn't want the standard game development model, that's precisely why we had to go it alone without investors, no-one wanted to know about a huge sci-fi game back in 2012, if it didn't have swords and dragons with magic it didn't get a look in.
Did you know, Star Citizen is the only AAA game ever to be made with NPC's that are able to communicate with the deaf because they will use American Sign Language? The mocap has been done. Do you think EA, Ubisoft or Bethesda would do such a thing? We can, because we know we will pay for it and wait for it, time is the precious commodity few investors want to give in abundance.
If you want to buy a complete game experience for today, this project is really not for you. If you want to know that you contributed to something unique and beyond wildest dreams for years into the future, then yes - help us all make that dream a reality.