Well, if you ask the folk over at Red Hat, they agree. And they're doing it within their code, which is both working
and simultaneously making the old-timers very, very angry.
They've been sponsoring GNOME, which has been pushing the simplified, mobile-friendly look for almost a decade now. They've also (I believe) been behind the scenes in GNOME's push to kill theming on the behalf of developers who hate their apps getting themed, which of course distributions hate because that hurts the ability to stand out. If GNOME looks the same on every distribution, your distribution sticks out less.
Red Hat has also been behind sponsoring SystemD, which for better or worse brought every distribution kicking and screaming into a more consistent "low level" layout. Again though, this makes management across Linux systems somewhat easier, while making distribution-specific differences smaller.
Red Hat has been behind Flatpak, which compartmentalizes applications and means that they can run on any distribution when built against a common runtime. For app developers and new people, this is great as a "Linux app" just runs on any "Linux" distribution, easy. For old-timers and technical folk (even on here)... again it's with kicking and screaming. And if you are a distribution author, every distribution now runs the same apps, so what's so special about your distro again?
Red Hat has also been behind PulseAudio and PipeWire, which changed how audio worked on Linux... again with kicking and screaming.
The point is, Red Hat keeps working on technology that, I would argue, makes Linux more consistent and approachable to newcomers, but massively changes how it works which angers old-timers and also happens to reduce diversity within distributions as to how things are done. This makes things easier for programmers, but erodes away the proliferation of distributions because the differences between them get smaller and smaller.
Because, if Red Hat gets their way, consider: Every desktop that uses GNOME looks the same because there isn't as much theming. Every desktop runs the same apps using Flatpak. Every desktop has similar low-level internals with SystemD. If you are a distribution maker, not much left to stand out now, is there? Again, app developers love this, but if you are a distribution maker, Red Hat is trying to kill your edge.