There are really 2 separate issues being discussed here.
1. Scale: how big or small the game actually is.
2. Model/Genre: Games as a service Vs Single player RPG.
Not to re-hash everything that's been said about Games as a service, I'll just say, that Model is arguably "Bigger" in Scale than any single player game, as it requires continual content update, server maintenance and usually a cosmetic shop to fund those two things. So, calling that Model "Smaller" is not entirely accurate.
Personally, I believe the series started as single player narrative driven RPG and should stay that way, Multiplayer modes or spinoffs are cool but "Mainline Entries" should stay Single Player focused RPGs with any online components secondary.
As for Bigger or not. Bigger doesn't mean better but smaller doesn't mean focused. The game should be a quality RPG with immersive stories and characters and systems, with fun fleshed out combat that is fun moment to moment gameplay. The Scale should be approximately as "large" as expected from the genre, A solid "Critical story Path" with enough interesting side content to make the world worth exploring. The thing is what the game REALLY NEEDS is quality, I don't care if its 150 hours to 100% or 60 hours to 100% as long as the content is quality. Interesting fully fleshed out characters and stories, interesting areas, minigames that feel worth repeating relationships that feel worth pursuing beyond getting the one unlock and then it just sort of ends.
Yes add some endgame/repeatable content to give incentive to continue exploring and playing beyond the "Main Story" sure make the map bigger, if you can populate it with interesting locations, Honestly I expect a return to Night City there is so much Unused space they don't need a bigger map, just open up those areas and populate them with good content and that would make the game feel twice as big, on the same size map. But a game can feel really "Big" just by making everything immersive and worth doing.
And of course, the main thing they need to improve is player choice, there is the illusion of choice in this game, but only a few have big consequences, most end up the same with slight variation. A bigger impact on characters would be nice. I like the Idea of just being one story in NC and not having a HUGE effect on the world overall.... but some visible changes or impact would be appreciated, other than people returning to normal business after stopping a crime or clearing an area, it felt like very little the player did mattered, The side characters stories felt a little like they mattered, but because the interactions were so limited once that story ends, you didn't really feel the impact, and player choice was meaningless really it boiled down to did you finish this or not.
So sure, It doesn't need to be "Bigger" in terms of map or Time commitment, but the systems need to be better in terms of impact immersion and overall quality.