I am eternally skeptical of the argument of old games being better and modern fans being dumber/inferior in some way. I think that the latter argument is always untrue, though the former argument is usually untrue but can vary game to game.
There is some validity to the claims, however only to certain extents.
"Old games were better" has the truth of "Old games were generally more complete when released" - Back when you couldn't just ship patches out the wazoo (Also back when gaming was more niche so it was more gamers making games for gamers and fewer corporates making games for shareholders) there was more emphasis on making a polished, functional product out of the gate. While most modern games aren't finished until a year after their release (If they finish at all).
"Modern fans being dumber/inferior" has the truth of games being more mainstream, so you get more casual gamers. You have things like whales funding terrible MTX practices, you have kids eating up slop like CoD, FIFA and Ubisoft games that are churned out using copy/paste as well as game "Journalist" types that cry whenever a game doesn't hold their hand through the entire experience...
These aren't end-all-be-all terms though. There are plenty of games being released that are well polished on release, that are designed for gamers and not shareholders. There are still hardcore gamers that want good games that don't hold their hand all the time.