Objectively this isn't true as CGI technology has improved by leaps and bounds (think e.g. subsurface skin scattering in new vs old Gollum), however there's a lot of other factors at play; old CGI used film tricks to make it blend better, new CGI uses full CGI and digital whatsits and doesn't care anymore. It also depends on budget and what studio takes care of it. Good CGI is invisible, and there's a number of non-superhero films where the CGI just isn't visible / you're not even aware of it. Anyway, what 20 year old CGI are you thinking about, and what are you comparing it with? I'm thinking The Spirits Within (2001) or Beowulf (2007); the former did not age well, the latter was already panned as having poor CGI when it came out. Avatar (2009) pushed the frontier again I think.
> go home to play video games and the new releases are all remasters of 20 year old games because no-one knows how to do anything any more.
This is a blinkered view of reality; there's thousands of game developers outside of this bubble, from single person developers making modern classics like Stardew Valley or even Minecraft when it first came out, to teams of developers that are bigger than those that made the games of 20 years ago.
Also, your opinion isn't fact; in the top 20 best selling games of 2024 [0] there is only one arguable remaster (GTA 5, which is on its 3rd remaster) and two complete remakes (FFVII Rebirth and CoD 3), with the former being a completely different game compared to the original. I share your cynicism about the "top of the line" video game market today, but you're not correct.
(meanwhile I'm playing 2007 video game (Supreme Commander))
[0] https://www.gamespot.com/gallery/2024s-best-selling-games-in...