Scott Jenson - who worked on the classic Mac for Apple, and Android for Google - recently gave a talk on this:

https://youtu.be/1fZTOjd_bOQ?si=BVOxUPjoULhwiclE

The tl;dw is that copying UX lets others invest energy in identifying the paradigm. Linux, which tends to be starved for resources, has historically been reasonably well served by letting Apple and Microsoft define UX, while Linux focuses on implementing it. However, those headlining companies haven't been investing in desktop UX excellence in recent years. It's time for open source projects to embrace experimentation and take the mantle of cutting edge UX, because Apple et. al. aren't paving the way anymore.