Well if you really want to get down to it, progression in video-games was originally just a high score and a free life every 10,000 points. Funnily enough, Elite was one of the first games to really challenge that idea and met with some resistance to begin with. With that said, progression in video-games nowadays has really hit a brick wall with this continually refined formula of calculated grind and reward. E.g. daily quests, gear treadmill, levels / rankings etc. When you say "RPGs have always used this" let's not forget that RPGs that used this also could have involved back-stories (e.g. Ultima Underworld), and are themselves descendant from traditional pen and paper RPGs where stats and levels offered players and dungeon masters a way to measure progress through a campaign that was heavily story based. What we see in new games is a heavily modified form of progression that employs obvious psychological ploys to keep players hooked. That the suggestion to have everything available from the beginning of a game is met with cries of "but what would be the point of playing?" or "no you can't have that, it would be unfair for players who have put in the time" seems to be a result of the indoctrination of gamers at large into this form of game design. Doom, Duke3d, Quake, Half-Life, Starcraft, Total Annihilation, Operation Flashpoint and Minecraft are a shortlist of games that I enjoyed massively that did not have this disgusting form of progression seen in modern games. You know what they had instead? Endless replayability through modding tools such as level/map editors and the ability to script your own missions and campaigns.
The future of progression in video-games is not grind, it's user generated content. You read it here first, folks.
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Just an interesting anecdote after having read your post again - you state your assumption that the OP probably plays his games by immediately unlocking all items and levels at the beginning through cheat codes, which you seem to think is a guaranteed way to ruin the fun that would otherwise be had. The very first day I got Half-Life, before I even played the training levels, the first thing I did was to install Worldcraft (the mapping tool) and make a simple room with every monster and weapon available in the game. I had built my first simple level (two rooms, a hallway and a switch operated door) before I even set foot in Black Mesa. Over a decade later and I was still making levels for the game, and had finished it, and had an absolute blast too. I suppose some people really do just want to have fun
I've been a modder myself, personally for my own use and making mods for others for online games, so I understand exactly what that brings to games that have a set story and end point in them, replayability.
This isn't such a game, it has no storyline, no end game, no high level content. It's an MMO, in the most basic sense if you play Solo, but still an MMO being run by the people who created and are still creating the game. There won't be mods, there aren't cheat codes, just like other MMOs, because WE don't get to change the world setting that the devs are running, it's THEIR gameworld, not ours, we just get to play in it. Big difference there, one that many people simply don't get or understand and they don't like that either.
One small thing...Doom, D3D, Quake, HL, Starcraft, TA, you don't start off with the all the toys, you have to progress through the GAME to get them, be that by finding the next powerful gun in the level or by actually building up your resources to create the new toys, you don't start off with those toys though. I loved those games myself, I actually created my own maps, levels and mods for all of them, and their successors in many cases. I worked with mod teams for games like Tribes, Tribes 2, Battlefield 1942/Vietnam/2, and it was fun, but the mods we created did nothing to extend the gameplay, we created NEW games essentially, so that's a very different thing. And in the BF mods, we actually didn't give you access to everything off the bat, we actually gated new toys we'd created behind actions or finding hidden locations or actually having to level your character up with our BF2 mods. And you know what, we did that because in games that give you immediate access to everything just aren't as much fun as having to earn something ingame. We knew that as modders, the players of our mods agreed with us on that and asked for MORE stuff to be done that way, it gave a sense of accomplishment when they acquired them.
I've used cheats and tools to give myself whatever I wanted, max level, etc, and you know what? It totally ruined the experience. It's fun at first, to walk around and just waste anything and everything, but there's nothing to find because I have the best, there's no point in doing anything because my character is already maxed out, and beating the bosses was pointless and trivial. It removed the fun from the experience totally. Some people don't want the GAME, they just want to be as powerful as possible right away and that's it. They don't see any point in the story, the plot or the experience of the game, they just want to be a god. I pity those people, they don't actually get to experience the game, there's nothing there for them. I completed Doom2 on Nightmare mode using the cheat codes, and it was...empty and pointless. I did it again using nothing but my pistol and it was amazingly fun.
Oh, and user generated content has been around for decades, since the 70s, it hasn't supplanted the professionally generated content yet and is unlikely to do so.