> what does macOS offer a power user that Linux doesn't,

Quite simply, an OS that you don't have to think about. I moved to MacOS from linux after seeing my co-founder use their Macbook basically without any problems, much longer battery life, nice conveniences like shared clipboard and wifi password sharing, airplay, Airpods integration, better screens and font rendering, perfect migrations to new hardware, etc.

While I learned a lot tinkering with linux for a decade, at some point you can't beat something that just works.