1/4" tripod socket is the best common option. I use it. No point there because the user don't use it. Don't undertand why remove a standard? Optical remotes? I don't take selfie. I press the button. Wifi? lol, no thanks. I want a camera not a phone and I don't want 1 hour of battery. Battery problem? where? just buy battery pack...
2. Optical remotes aren't for selfies. Smartphones on stupid sticks are for selfies.
3. Most new cameras have WiFi. It doesn't affect battery life when you're not using it. They're just usually really slow, so picture upload/sync that should take 1 min tops take 1 hour instead.
Remote live-view and exposure/focus control works quite well, though, as it doesn't need that much bandwidth. There's also BLE, which in my camera allows remote control from smartphone without affecting battery life in any measurable way (BLE consumption is negligible).
4. Camera batteries are insanely expensive (and no, they don't contain anything magic or special, unlike what they want you to believe—apart from DRM, they're completely standard batteries worth about $20 retail when branded), they're DRM'd to avoid third-party manufacturing (which leads to more recent battery copies being unable to show charge level due to skipping this circuitry), they're often change shape just to force you to buy new batteries and chargers instead of reusing them, they don't support common charging specs (USB and Qi, for example—it would be practical to be able to juice up the camera while its in the bag between shootings), ...
There is nothing but battery problems.