Here is where I’ll disagree, a tools usefulness isn’t defined by its features, but by its users.

IA Writer, Bear, Ulysses, and all the other markdown writing tools are only as useful as you want to make them.

If a tool doesn’t have <insert fancy feature here> and you discard it then that doesn’t make it a bad tool, it makes you a poor user because you can’t see past your perceived wants to realise all the other brillant things it does.

I understand why you like Notion, but I find that tools that tout a Swiss-army level of features often make for massive productivity loss. You end up too busy twiddling dials and flipping switches to realise the thing you start out to do – in this case write – is the last thing you actually ended up doing.