I always reccomend the gen 1 iPhone SE to anyone that wants a "modular" phone. No, you can't upgrade the parts, but you can replace them when something breaks.

I always reccomend the gen 1 iPhone SE to anyone that wants a "modular" phone. No, you can't upgrade the parts, but you can replace them when something breaks. I'm going on 5 years now with mine, and I've replaced nearly every component but the main board. I've replaced the lightning connector, main screen, main camera, headphone jack (remember those?), battery twice, even the SIM card slot. Everything is just screwed down (no glue) and replaceable with a $7 toolkit from Amazon. Parts are dirt cheap and readily available on eBay. And it's still getting the latest OS security updates 5 years later.