How do i leave a band politely?

Hi! Im a bassist of 5 years now and im in a small band with some friends. We've been playing for just under a year. I am friends with these people but a lot of things have cane up resulting in me not wanting to be in this band. This includes but is not limited to:

-I am the only one who knows any more than basic theory

-I want to focus on myself and my school work atm

• They are making whole band decisions without asking me

-2 members of my band are being super arrogant and narcissistic about it even though they are actually really nice people outside of band

-I genuinely just dont want to be in a band with them

-I have completely different music taste.

(also i do acknowledge that i am far from perfect compared to them lol)

Sorry if this just seems like a ranty vent about things but any help would be appreciated as i dont want to stop being friends with them. Thanks!