Why would I discount the most popular applications of the kernel? That is almost the whole userbase

That is an entirely different argument which I did not contest and the comment I have answered to did not make

EDIT: Although, it depends on what we define as “bigger”. Binary size is certainly bigger, but user adoption is abysmal comparatively.

But what about Linux distributions compiled without GNU tools? Most popular Linux distribution’s kernel currently is compiled with Clang, not GCC, and as far as I am aware does not include anything from GNU. Of course Linux is historically influenced by GNU, but in current day and age they are orthogonal

On Android I use Re:Work, like interface the best. Before that I have used previous app from the same developer (I think it was Nine mail?).

On Windows I really disliked Thunderbird, so currently testing out emClient.