Small size. I'm a 6'2" male, so my hands are probably pretty well above the population average. Maybe it's because I'm a lefty, but I hate how big phones have gotten. It makes one hand use almost impossible, and if it's that hard for me, I have to assume that most people have just given up on even trying. I'd really prefer a sub 5.5" phone screen (part of me wants to say even smaller, but it's been so long since I've used a phone that small, that I don't even know anymore what my ideal size/lower limit is).
Headphone jack. Relatively self explanatory, imo.
No camera cutout. I hate them. I'd literally rather give up the screen real estate and have a bigger top bezel (although, see my point 1, I obviously value screen size less than most consumers). Luckily in Android you can just turn off the screen around the cutout in developer options, but I'd prefer to just not have the screen there. At least on my current phone, it still wastes battery (this might be a non-issue on OLED screens) and will register touches, preventing proper touch recognition elsewhere (this is related to the difficulty of single handed use, would probably be mitigated on a smaller phone)
SD card slot. Maybe the easiest of this list to actually still find? It seems like a decent number of phones these days have a spot for it in in the SIM card tray. I've heard that the reason companies don't include it is that a lot of SD cards are trash and wear out pretty quickly. This could lead to consumers losing data and being mad at the phone manufacturer. In my opinion, this is understandable, but still a bad reason.
IR Blaster/FM Tuner. I consider these two together. They are both pretty niche, and are "nice to haves". Mostly because I want my phone to be as much of a general purpose communications device as possible. The times when these are helpful are infrequent, but in those rare times, extremely nice to have.
Replaceable battery actually isn't on my list, mostly because I consider it part and parcel of "repairability", which (maybe nonsensically) seems like a different category. And, for me personally, battery degradation actually hasn't been a problem for phones. The two biggest things I would want to be able to repair are charging ports (this would be mitigated with wireless charging) and screen repair. These are, for me at least, the two most likely parts to break/wear out, and in my opinion they should both be cheap and easy to repair. Of course, if it was easy to do those two, you'd get battery replacement almost by default, and I certainly wouldn't be mad about easier to swap batteries.
