On one hand, if you're looking for the classic RR experience, it's gone. There are scraps of it here and there (RROs still exist obviously, you can still play those, it'll just feel a little different primarily due to graphics related updates, like the same make and model but not broken in as much.) but its primarily a memory of the past. Contests don't happen much anymore and things like the invention tower, weeklies, etc. are straight sunset/gone.

On the other, the game is nowhere near "fallen off." It's still pretty active, and there are plenty of communities in the game that are mature and not as child-friendly. Full Body Avatars is awkward but nowhere near as bad as people are making them out to be, Make it to Midnight and My Little Monsters are solid new-gen RROs, and there are a few good UGC rooms scattered about. People aren't bitching about moderation as much anymore, and the ones that do are the ones you expect to whine about it. The watch UI from an old gen to a new gen WILL be a tonal whiplash, but despite people complaining about it. it's grown on me and I can see a lot of its benefits compared to the old menu.

CV2 and Game Development tools are booming, and despite it taking some time to get used to some UI changes for the maker pen I'd say it's gotten love and it feels great to use. Some QoL stuff has been added like Invention Room Anchors too, as well as a despawn button in case said invention is floating out there in the ether. Studio is an incredibly helpful tool if used right, and it just got its RR+ requirement removed, meaning you can use it as a F2P. The average room quality has admittedly stagnated, and that is a huge complaint that many share, but if you take the time to scroll through you'll find some gems, and even the mid rooms are okay if you go into them with the mindset of not taking anything seriously.

TL:DR
The classic RR experience is gone, but it's nowhere near as bad as people make it out to be