When was the last time you felt excitement for a macOS release? Me? Snow Leopard. When I transitioned to Linux I rediscovered OS excitement. I'm on KDE Plasma now and every update has exciting features that serves my interests.
I think Apple realise this. There are no genuine new OS features to be added, so they just shuffle things around so that things are changing and thus seem fresh and hip. For anyone who cares about stability and doesn't want to relearn everything they shuffle around, this is nothing but a negative, but Apple et al. have no other levers to pull (well, there's the AI lever, but that's also generally not a positive in and of itself).
Maybe there are new OS features that could be useful, but creating and integrating them in a way that's actually helpful is just such an ordeal that nobody will do it.