I’m also happy with the mail app as it is. The spam + sorting + archieving management I do on laptop and not on phone. When on my way I have no time and mood to care for spam. (edit: shifting a single or few spams to spam folder is easy enough for me) When at home, I have also a laptop and spam filter.
My idea was more meant to make SFOS more attractive and usable for a wide variety of users needs and wishes, and so more addressed to @Jolla .