Had to, the battery in my iPhone X was on it's last legs. So as much as I HATE it I had to do some research. Granted, my research is easier than yours probably is because I'm 100% Apple - computers, phones, pads... so I didn't have to bother with looking into Android. (Not saying Apple is better, I don't think it matters - but no way am I going thru that mix and match tech crap ever again).
So there is price... that's always the 1st criteria, processor, resolution, type of camera, battery life (my top concern), and on and on and on.
Called up some comparison charts.... saw a youtube or three demonstrating processing time, etc. Studied until my eyes blurred and my brain vapor locked, (about 5 minutes), and made my decision.
Got the iPhone 11 Pro.... it comes in "Midnight Green" and it's pretty. I don't know how big it is... got confused by too many models to compare... don't know about it's resolution, or what processor it has..... but it's pretty. - JamesJM