To be fair, some ways of holding the weight of the phone in one hand, e.g. resting the weight on your pinky finger along bottom edge, can cause hand injury/RSI. So weight isn’t a totally solved problem.
Does this actually cause hand injury? The bent-pinky-finger social media panic was easily defeated by realizing both of your pinkies, not just the one that holds your phone, have the same bend: it’s a knuckle.
Not the bend. Just that it hurts if you hold it like that for too long :(
Try to get one of those holders that magnetically click to your iPhone. I don't want to say the brand, but something with socket. They are an RSI-saver.
I started to use those stand cases, and I'm not going back. They Make the phone so much more thicker, but also make it so much easier handle.