Just a couple of cents:
I started way back when the game came out. I wanted to get a big ship and fly it around. I got to a Clipper, and then put down the keyboard for a while. Like a year or maybe more. The Conda was soooo far away.
When I came back, I didn't have Horizons, so it was basically the same game. I played for a few weeks, found that hauling poop was really profitable, decided I was back in, then bought Horizons. Wow, there was suddenly a ton of stuff to do now that I could land on planets. That, to me, was a huge increase in the number of things to do.
Now, I've recently ground my way up to a Cutter, and have it fairly well spec'd. It's a totally overpowered beast, and I love it. It's all I ever wanted. So after this past weekend, I was trying to figure out what to do now that I have my trophy. Sure, I can get Elite in things, but who really cares. It's an achievement that comes with no bonuses. I can drop into RES sites and fight for hours on end with my shields never going down, which is cool, but not a challenge. I am truly one of those people that has goals, does what is available to achieve them, and then plays with my new shiny toy.
So, what I wanted:
1. Corvettes and Cutters in RES High sites and assassination missions. I need a challenge.
2. Maybe take a trip to Jaques. I've never been that far, but there are like 300 jumps from here to there on the Neutron Highway, and that's a lot of jumps. But at least with the Neutrons, it's engaging to overcharge without blowing up.
3. Multicrew Mining Ship. That could be really fun, having a couple buddies on the guns and a fighter while I mine stuff. This will be happening.
But, one post earlier made me think big. Fallout 4-style settlements. A crafting system where you mine or trade things to make other things, instead of just sell them. Hire a staff of NPC captains to fly your trades around for you. Hire an engineer to build a new type of space ship for you. There would be a reason to login every day and check on your progress while you were away. I think that's a massive reason to keep playing, and a reason why all of the pay-to-play apps have gotten so profitable.
So, I don't think that the game is lacking, I think that it has immersion, and I feel the Horizons line of updates have been beneficial, but I see room for improvement in the big scope. Hopefully these things will come, but until then I'll just be flying a giant ship which is amazing.