But aside all the assets in city (just like in any open world games: WatchDogs etc.) GTA games don't have much content at all, there is nothing to do in single player once missions are done - they don't make tons of side missions like in W3 or even AC:V. GTA5 took 5 years, normally we would get GTA6 after 5 or 6 more years but Rockstar didn't give a fuck, they just made some stuff for GTAO and RDR2, GTA 6 wasn't in development at all.
I think if the console shortage is figured out then we will see it sooner.
They are only doing current gen and PC, so that bodes well for a leap that'll be jaw dropping.
If chips are sorted by end of this year, consoles install base is done well by end of next year, then 2023 seems plausible.
With all this development time this better be a monster of a game in terms of content. Polish they excel at imo looking at RDR2, and while it certainly has a lot of content, this game should trump it big time.