Resale value maybe, but I'm finding phones are just generally lasting longer these days. My phone is coming up to 3 years old and I have no inclination to upgrade. It doesn't feel slow, all the apps still work, its running latest OS. There was a time when I was upgrading every 12 months but that just isn't the case anymore.

High resell value just means you can't get cheap old products. I spent about 300$ on phones in the past decade. I buy used android for ~100$ and use them for 3-5 years. Never had any issue.