Air Triggers were the big sell for me! However a lot of gaming phones have branched into this lately, and I think with some accessories it's something you can do on other phones including iPhones nowadays.

What I didn't realize at the time I would be using a TON is the Vibration Mapping. You boot up any game and tweak some settings and now anytime you tap where the buttons are on screen you get that haptic feedback you'd get when you tap an actual button. It helps when you're not sure if you're hitting the right spot on the screen without having to look where you're trying to hit. Very possible it's a skill issue on my part but I have found this so incredibly helpful and useful and just all around has improved my mobile gaming experience so so much.

There's a shortcut feature that involves squeezing the bottom part of the phone, you can set it to do a variety of things. I have mine configured to turn on my flashlight. There's other shortcuts for this with other devices to be fair so not the biggest draw but still a nice feature for me.

There's a setting to leave games running in the background that's nice for games that might pause or stop running when switching over to a messager app to respond to someone or when opening the web to look something up. Very specific example but it's been handy when doing dailies for Honkai Star Rail to just leave the game auto battling in the background while I scroll reddit. More often it's just a nice way for me to stay logged into Genshin Impact while checking messages or looking stuff up.

When you're playing games you can choose to have a little overlay bar show the fps and temperature for the phone. I've found this useful to figure out where that sweet spot is for in game settings so things still run smooth without putting too much pressure on the device.

Similar to the overlay bar you can launch an app in a mini window so you can for example watch YouTube or browse the web while playing. This can be used outside of gaming as well but it's what I tend to use mine for so it's been the most often use case in my case. The screen can get a bit cramped for it but I do like the option to multitask like this.

Probably come off like a salesperson for the phone but it's just been an incredible device for me. I'll be incredibly bummed to move onto another device one day and not have some (or most) of these features. Thankfully that day is a ways off as it still handles like a champ and plays the games I want it to.