I’ve carried my 12 Pro for 3 years, which is the longest I think I’ve kept a phone (worked in wireless for a good while and had to keep up with latest devices so I could sell them, and it became a bit of a habit to upgrade regularly). My 15 Pro Max comes in tomorrow and I plan to use it for 3-5 years. I’m upgrading specifically for USB-C so that now all my devices that get used regularly have the same port. I’ll give my lightning cables away so they don’t just become e waste immediately and that’ll be that.