I have 3 Gmail accounts and receive mail constantly. I also hate the Mail app on iOS.
On Android, there are a few key behaviors for me...it groups mail notifications by mail account, it lets you hold down to see the sender/subjects of the first few for each notification bar, and it only buzzes to notify you on the first email of each account. For that last one, I need to know when my inbox is empty if I receive something for work because it might be urgent. Unfortunately, the iPhone owuld buzz for literally every single one, and the Gmail app had no way of configuring it like Android.
Also don't love the fact that I don't have my widgets like I do on Android--they just don't compare.
That's exciting to me. There are some people who highly value Apple's HW engineering but don't want to deal with the closed ecosystem.