Not really.
The B1W do take a single picture at the start of every segment, but there are no cameras that take a picture every second or so ( though it have to be more of than that that for a car and the fast paced environment they move thru )
you are right that if you pause a video or go thru a video footage frame by frame you will notice poor IQ you dident really notice at playback, this are mostly to do with the way our eyes work, and out brain extrapolating on what it assume things must be / look like.
But even if you are snapping individual photos and not video frames, the problem will be the same, and in general this are down to the exposure timing the camera choose to use, and if there are little light then the camera drop / slow down exposure so the sensor have time to collect more light. and this are also fine IF ! there are no movement ( which there always are in dashcam footage )
The best low light performing dashcams use the Sony MIX 291 sensor today, but thats still just a 2.1 megapixel sensor with just enough pixels to capture a 1920 x 1080 image, and the reason for that is the individual pixels on the sensor are large and so better at capturing light.
you can have another sensor with the same physical size but then have 20 megapixel, but to make room for all those pixels on the sensor they have to be much smaller and so worse than capturing light.
Now you can get sensors that can capture stunning low light footage too, but then we are talking about full frame sensors or larger where you have room for the large individual pixels and still have them large and light sensitive.
And then we are talking a whole other ballgame when it come to price, you will probably have to put at least 2 more zeros on the price tag for a camera with that kind of hardware.
With the technology in todays dashcams you can really only expect plate capture ( even of large simple EU plates ) in the best of weather in the daytime, it dont even have to be late evening for dashcams to start struggling with illusive things like plates on cars.
There are tricks like pixle binning on some cameras, this mean the camer bin 4 pixels on the sensor to act as one and so more light sensitive unit, but doing that you of course sacrifice resolution.
This we have not yet seen in dashcams, but i recon we will see that soon, and personally i dont think its all that stupid.
Say you have a sweet sensor with the +8 megapixel it takes to record nice daytime 4K footage, when the light then dim the camera could change to binning and so just have 1/4 of the resolution but then be much more light sensitive.
BUT ! you should not focus that much / hard on plate capture, if you do you will never get a dashcam, of pay over the moon for something professional thats not really a dashcam.
And trust me any dashcam are much better than no dashcam.