Form factor
Issue for me is form factor. All phones are basically the same in every way, aside from some software quirks. Hardware has homologised into a uniform slab of glass with identical human interface design issues. They all look the same and feel the same.
Buttons on the side? Shit. Touchscreen keyboards? Shit. Screen bezels that go to edge and cause all sorts of issues with fat hands holding the thing? Shit. Screens so big and unprotected, easy to break despite good quality build? Shit.
Give me more flip phones, more bananas phones. Experiment with new form factors FFS.