These things are very over powered for what most people do with them, and that’s been true for a while. Remember Deep Blue, the supercomputer IBM made to play chess against Gary Kasparov? iPhones have had more processing power than that for so many years I can’t remember how long it’s been true.
Unless you want to use a new feature (and there aren’t a lot) or do some really demanding gaming, or need to send an emergency signal by satellite if you’re out of cell range (that was new in the 14), you can use an iPhone for 5 years or more without missing out on anything.
I didn’t see the first post, but I looked at it just now and given the value here I’d advise asking your real estate attorney whether the contract covers this…