I'm still using an iPhone 11 Pro that I bought used, it's now almost 5 years old and still very, very usable. I did have the battery replaced about a year ago,

I'm still using an iPhone 11 Pro that I bought used, it's now almost 5 years old and still very, very usable. I did have the battery replaced about a year ago, but unless I break it/loose it, but I can see myself using it until Apple stops making OS updates for it. Even then, they seem decent at pushing out security fixes for old phones (I believe the 6s got a patch recently even though it's 2 versions behind the latest version).