Just to add a different perspective: I never used a case for any of my iPhones or iPads. I refuse to hide that mostly beautiful body in a cheap, or even high quality, permanent case.
And yet I have still sold all of those dozen devices in flawless, virtually pristine condition when it became time to upgrade. I think the secret is to use a lightweight, thin textile sleeve [1] during transport, in your pocket or bag. Plus, it also serves as a soft bedding when your device is resting on a table or other hard surfaces. It also has a microfiber inner lining, which combined with the snug fit keeps the display clean.
Sorry for sounding so ecstatic about a sleeve, but I always wondered why temporary sleeve usage wasn’t more popular compared to those dreadful permanent cases.
[1] https://shop.fitbag.de/jive-grau-handytasche-nach-mass.html
edit: I thought I was replying to the grand parent. Well, it’s not a different perspective then.