Obviously Wizards is going to insist that any games currently being made are going to use the current rules in order to promote their brand.

But I’ve been playing DND since the 90s and I think 3/3.5 was trash, and so do all the people I play with (also long time table top vets). If you like those rule sets that’s cool, but 5E doesn’t just appeal to new players. Lots of older players appreciate that the game is significantly decluttered and less convoluted now.