https://rationalwiki.org/wiki/Good_old_days
All I can say is that modifying a current game or creating a new game in 2022 that is similar in design to games that came out twenty, thirty years ago, wouldn't appeal to enough players to be profitable. We aren't at all the same gamers that drove the industry in 1999. Time has moved on, and relevant gamers (13-25?) today simply want different things, namely, faster gratification and solo play.
Watching the times change is simply part of life and getting older. I could sit here all day and pine for the funk to come back to hip-hop (funk-sample-laden hip-hop went out of style two decades ago) but it just isn't. At least, not any time soon. 'Kids these days' just don't want the same things, and it's the 'kids' that video game (and music) businesses care about, for the most part.
It's alright to be nostalgic, either via thoughts, or tangible enjoyment of the past; reasonable people do it all the time. IMVHO it's simply futile to push for MMOs to return to decades-old styles, the same as it would be futile to advocate for GTA VI to be a top-down 2D action game, even though those are its roots, and many people (including myself) have very fond memories of playing that original GTA until the sun came up.