Thank you for the ask.
Personally, I recommend Genshin Impact. It looks like it’s compatible with a good amount of iPhones. It’s free, with a good story and all sorts of activities that are both fun and relaxing. You can get your usual combat in a moderately paced manner and also spend time climbing every surface available and catching lizards and frogs when you want something stupid to do. Character progression is a bit different, but still a lot of fun. You will unlock additional parts of the map when you’re more ready for them, so don’t worry too much about that either.
Fyi… You can also hang-glide back down off of every surface you climb up once you get your hang-glider. That happens fairly early on in the story. It’s a lot of fun, but be careful in lightning storms. I found out from the friend that introduced me to the game that my fear of getting struck by lightning was valid and came with a hidden achievement! Hah!