Despite what the article claims, I really don't see much new in what Roam does over any other note taking app or wiki. --Whether they have more or less structure, they all let you link pages together, so hierarchies are generally up to you to decide if you want more or less of.
I use OneNote since I already have O365 anyway. To convince me that I should pay more than 3 times what O365 costs, you'd have to be able to show amazing improvements, and Roam just doesn't.
Seems similar to Mindforger ... Mindforger I think uses ai or something to 'link' internally between docs. Just found it the other day, but it's free. so -- I'll probably stick w/ that.
I use OneNote since I already have O365 anyway. To convince me that I should pay more than 3 times what O365 costs, you'd have to be able to show amazing improvements, and Roam just doesn't.