I really don't see a problem with newsletters. If one starts getting too dull or is no longer of interest, I unsubscribe.

Functionally, they all work the same and all have the same unsubscribe link at the bottom. It's not like the bad old days anymore when you were signed up to lists you never signed up for.

Unless your use of newsletters is different to other people's, I don't see what problem you're trying to fix.

Why are you signing up to newsletters you don't want?