What would be the advantage? Why put in all that work just to reinvent the wheel?
[1] https://news.ycombinator.com/item?id=1878220
[2] https://common-lisp.net/project/mcclim/excite.html
In classical OS (Linux, Windows, Mac) the developer is responsible for seemless integration (in KDE or MS Office for instance). It is easy to break design guidelines here which causes ugly interoperation, or even lack of interoperation.
At least in part, because of storage and memory constrained things like home routers.