I still have my XS Max, and got the Note 10+. I go back and forth between iOS and Android regularly.
1. I love the screen. The boxier shape feels like it's a bigger than .03 inch increase. Plus even though my Max has a beautiful display, the 10+ display is that much better.
2. iOS just gets boring after a while. I love a lot of what Apple does, but their refusal to update the UI is maddening to me. That and the overall customization Android in general brings is great.
3. I really wanted the ultra wide camera. Of course the new Pro iPhones just announced have those, but it's yet to be seen how well they'll preform.
4. Overall form factor. I just like the way the Note 10+ feels and looks. The build quality has finally equalled what Apple does, and it's lighter. My XS Max feels like a brick in my pocket.
I'll keep adding as I think of things.