Except the Linux userbase has been saying that exact thing for the past ten years, so again, has Linux also degraded in sync or, hear me out here, is this mostly a nostalgia thing that makes you forget the cludgy performance issues of the software you used when you were younger and things have mostly gotten snappier over time across the board?
As a current dual booter I'll say that Windows and Linux don't feel fundamentally different these days, for good and ill. Windows has a remarkably crappy and entirely self-inflicted issue with their online-search-in-Start-menu feature, which sucks but is toggleable at least. Otherwise I have KDE and Win11 set up the same way and they both work pretty much the same. And both measurably better than their respective iterations 10, let alone 15 or 20 years ago.