Would you buy a new phone for this?

I'm pretty happy with my current phone. I was also happy with the phone before that. And the phone before that. There was no immediate need to upgrade my device but I did it anyway because I thought it would be worth it. Yes, the better screen, camera and computing power are nice, but overall improvements are miniscule. So a new phone is 0.1 seconds faster than an old one. Does that actually matter?

What I want to ask you is, what feature, possible or impossible would make you buy a new phone tomorrow. It could be anything, like a blood sugar tester embedded in the phone, hot-swappable batteries, modular phone, shell made from liquid metal etc. It just has to be worth enough to upgrade from your current phone, which I'm sure you're reasonably happy with.

I'd like a phone that would be virtually indestructible, but that would look like a smartphone looks like now.