I was looking into smaller form factor phones awhile back, and an interesting feature I noticed some of them had was a programmable button.
I don’t know that programmable buttons on phones are that niche, but it’s certainly not common either so far as I’m aware, so this super simple feature would be wicked imo. I’d also really like if more phones just stole Motorola’s gesture interactions (e.g. quick twist for camera, firm double-shake for flashlight, etc.).
Also, uh…Speaking of small form factor phones, I don’t know if that counts as a feature, but it’s one detail I’d like to see come back, or flip phones with separate screens (clunky, sure, but better than the screen eventually creasing imo).