A lot of what defines AAA games these days is that, as much as possible, every moment has some kind of hand crafted element to it, often not constructed from the core mechanics. In the days of half life and what not, distinct content was mostly in the form of level design and enemy placement and what not. In AAA games of today its from scripted sequences that are more movie esque. I think its a bad direction tbh. It's too expensive and, especially in an open world game, you end up with an uncanny valley of super deep and super uninteresting gaps of content. I think breath of the wild was the one game to make a more traditional approach work with open world content. There's NOT a lot scripted sequences. Most of the fun is emergent from a small but comprehensive physics system. You don't see a whole lot of new elements around each corner, but it works.

But if your goal is hip cliche AAA game, yeah, you need the huge team. I don't know if its much of a diminishing marginal utility of devs/artists either, so much as a sprawling tree of parallel but unrelated pieces.

The newer tomb raiders are the epitome of this to me. Every five minutes you're on a death defying leap with crumbling architecture or whatever. As close to the video game ideal of "every frame a painting".

To me, more successful "open-world" games these days are not that open, but are rather smaller, denser, and sometimes vertical. Sleeping Dogs nearly a decade ago and Yakuza now fit that paradigm, and do pretty well for it.

A handcrafted open world doesn't scale all that well, and Cyberpunk, from my impressions, seems to be both large and vertical, which makes the challenge even harder. Pretty much the only open-world I've enjoyed in recent years is BOTW, and that world is pretty empty, if only because the setting is literally an apocalypse where most people died. (In fact, for people arguing for interaction density, there is a collectible in the game that is revealed when it is 100% to be a pile of feces, specifically to make fun of 100%-ters.)

For CP2077 vs HL it's pretty obvious why it would need to be a lot larger, with the sheer volume of art assets, story writing, level design, voice acting, game balancing and engine sophistication required. But I'll be the first to echo your sentiment that there are massive diminishing returns on team size.

Of course in many ways AAAs have dug their own pit of despair with this, they throw so much investment into it that they need to make sure they appeal to as large an audience as possible and cram as much content as possible in, while also having an eye to DLC later down the line, the economics demand it. Hence why CP2077 had to desperately try to get it to work on last gen console, otherwise they'd be immediately removing a massive portion of the market.

As consumers we can get as much enjoyment out of some indie level gamer. I for one have play way more hours of The Binding of Isaac than any AAA title I've played and it would have been a fraction of the development costs.

I think the team size grows with open-world multiple storyline type games like Oblivion/Skyrim. I haven't played CP2077 but from the sound of it, it's in that realm. They have a core group that programs the actual mechanics, physics, play - but then separate teams create content missions and bosses (and boss fights). That's where the spend is. And a lot of people can play these games for a really long time because there are a lot of different side missions. ... and eventually DLC.