I think my point is that wlroots is a set of building blocks, rather than a single library. You can't build an unopinionated single library that just takes care

I think my point is that wlroots is a set of building blocks, rather than a single library. You can't build an unopinionated single library that just takes care of the Waylandness of your DE, that you can build on top of. The compositing and the windowing and the event handling are all intertwined, so instead the best you can do is wlroots which gives you some blocks you can put together in the appropriate way. It makes for complex, significant work for any Wayland DE, with less shared work. I don't think this is wrong - it seems this is the approach we need to get full featured DEs, it's just unfortunate that that's how reality has worked out.