Actually unsubscribe from stuff. If they show up again, I hit report spam. No, I don't care if they were actually gonna stop after 14 days or whatever.
Have strict rules about how I use the inbox. If I read an email, and it isn't actionable or I don't need to do anything, I immediately delete it. _Maybe_ archive it if I think it could have CYA value like a receipt or something. Keyboard shortcuts help with this a lot. I can often make this call just from the topic line of the email, so I don't even read a lot of the less important stuff in my inbox.
The end result is that my inbox is a small (~20ish items on average) list of stuff I either need to do something about, or haven't read yet.
I don't spend much time on my emails every day. Maybe 5ish minutes. If you are the kind of person who has 5k unread emails and want to do this (used to be me), you may want to start by first declaring bankruptcy and archiving everything. I did it when I first started, turns out zero of those emails ever came back to haunt me in any way. The people in your life who are actually important or will break your kneecaps will eventually either come back or find you through alternate channels.