If you are expecting gopro 7 - 8 levels of image quality, you are going to have to wait a few years at least.
Its the same for the car cameras, while 4K are out there for a year they are falling behind in bitrate, for this to catch up to current day action cameras we will also need at least a couple of years, if it ever get that far.
Something will have to be dont i think, more and more are wanting action camera / phone camera level footage of dashcams, so to me the makers have to make that happen, or those people will keep using action cameras and never buy a dash / handlebar camera.
As it is now i would hate having a 4K camera unloading 100 mbit footage to a tiny SD card, doing that my action camera fill up a 64Gb memory card pretty fast, so in a dashcam situation one would need at least a 256 GB memory card, and double that would not be one bit overkill.
The situation are sort of the same with CCTV cameras, you can have a 4K camera at the entrance of a store filming every face / person that enter, but you dont need to do that in 100 mbit, far from it.
Even at H.265 recording that entrance all day for hours on end will need a lot of memory, so that camera will probably only do 25 - 30 mbit, which are also just fine for people funneling thru a set of sliding doors.
My 1080p CCTV cameras only do 4 mbit, and that's actually fine, though the one that cover the front entrance and have the main street in view do struggle with the cars pasing buy at speed, but i have no interest in them only people walking on the side walk and approaching the door.