Yeah, Substack's fun in a way, but there's an awful lot of crap in Notes to wade through. That said, it's algorithm seems very good at refining the feed in line with your interests.
Bolt a Notes functionality on here, and use Substack's algo tech for article and Notes distribution, and that would be a great platform for me.
Quite how you get the subscription/earnings thing to work is a different matter.
The recent talk on 'Stack about integrating an ebook sales platform really appeals.
So you don't expect to earn anything for your articles - maybe enough cents to get your $5 sub back, plus loose change - but it's a way of organically building a readership so you can then tell 1,000 people or so 'Hey, I'm releasing an ebook - here it is - one click and it's yours for $3 (or more for POD option'.
Plus, if you want to contact a traditional publisher, you have that email list of x thousand followers with an interest in you and your style.
That's what I'd like of a hybrid Mm/Ss model, I think.