What's the point of using K9 Mail over GMail or the default

You don't get the auto sorting into different labels. My mail getting separated into Primary, Promotions, and Social has been so fucking helpful.

>>62351719
K9 uses IMAP push rather than real push notifications which consume far more battery.

K9 Mail is a traditional email client. No calender invites or such. Plus you have to set a one time password for it as Google doesn't play nice with some email clients. The upshot is no ads or crap sorting.

I'd there something like K-9 that follows material design?

>>62354067
just look for k9 (material) in the fdroid repo on the Internet.