My old smart phone didn’t support DJI Fly app, so I had to get new remote. Decided on iPad mini, which is now always connected to the controller (via Miss Chrissy adapter).
No issues with 10 flight hours of usage on the original mini. The caveat would be that the pixel xl is large enough that, depending on the cell phone holder on the mini 2 remote, it may make more sense to go for a smaller cell phone. I have a backup palm cell phone which I have begun to use instead of the larger pixel xl. (Though the palm has it's own issues, namely contrast, when outside.