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?
What I have discovered is that everyone's approach to newsletters varies, and I'm just figuring out if there's a problem big enough for me to lend a hand to those feeling the newsletter chaos! Your input helps.
if you could solve any one problem to make your newsletter consumption experience the best - what would that be?