Lloyd Chambers, who always has good technical as well as users’ insights about photography has a good list of features camera makers need to add to their cameras. https://diglloyd.com/blog/2019/20191204_1100-camera-maker-goofs.html
I would add the following ones, focusing on things that are easy and not that advanced computationally:
– minimum shutter speed for auto ISO as a first class citizen and with richer control. e.g. use 1/200 minimum shutter speed until you hit ISO3200 then accept 1/125 until max ISO of 12800
– better control over ambient light/flash balance. for example ability to switch between Canon and Nikon behavior (match ambient vs. keep minimum shutter speed.) In general different settings for flash vs. no flash (e.g. different max ISO).
– ability to automatically alternate setting between shots in a burst. e.g. flash/no-flash. Or slow shutter speed for motion blur and subject tracking followed by high shutter speed to get a safe shot; or even slow shutter speed with lower ISO/higher shutter speed with higher ISO. aperture bracketing (with same exposure) for depth of field control.
– record gyro data for camera shake removal, blur assessment, and video stabilization. Record accelerometer data for e.g. automatic perspective correction.
– separate movie and still setting. e.g. I photograph and film kids, I want 1/200 for stills but then 1/30 for video.
– low ISO through frame averaging for long exposure (which is probably covered by some combination of your long exposure and frame averaging bullets although that wasn’t fully clear ).
– ability to start rating and sorting my photos in a way that translates to my software (e.g. lightroom)
– simple way to cycle through faces or potential AF subjects in case the camera focuses on the wrong person.
– better communication and ways to upload my pictures to my computer. When I am home on the same wifi they should figure out how to communicate.
– open the software ecosystem!