Yeah the notetaking in Notability is really nice. Really, really nice.
I think the frustration for me sets in when I try to use the iPad for anything outside of media consumption or note-taking. There are just limitations within any iPad apps that have desktop equivalents. It also doesn't help that I refuse to pay for the Pro line.
For me, I have found that I like the actual ability to exactly match software with my desktop (AMD, Nvidia 3060TI) with my portable and I don't have to have a third device. Before it was Gaming Desktop, then macbook m1 (with different software), and an iPad (with different software again).
Now I have a much more cohesive setup.