I've temporarily backed off Medium, but only because they're in the middle of working out the hiccups from opening up to 70+ new countries, which in the long term I think will be a big plus, since we'll see a lot of different perspectives. But right now, the platform is struggling, so my posts will be less frequent until they figure it out.
But, yep, both platforms are great.
When I was just starting on Medium, making comments was my version of Substack Notes. I gained a LOT of followers with my comments, because, apparently, people really enjoy idiots.
I have less success with Notes. Most of my new subscriptions come from restacked posts.