If you are disciplined and unsubscribe from mailing lists, you will stop getting most of the spam in your inbox. Sure, your spam folder might still be full - but with actual spam.
Honestly, I think it all comes down to discipline. You should immediately unsubscribe if you do not want someone’s newsletter.
But my problem is different: I get a lot of emails that I do want to receive, but I do not need to read them right away - or sometimes never. For example, mortgage monthly statements, which I really only need at tax time.