On the one hand that's correct. On the other hand you could completely avoid that if you did long exposures the way a Google Pixel (2+ I think) does it (in software):
Take lots of short exposures and fuse them. If the device is handheld you get variability in positioning for free, if it's on a tripod, it will automatically wiggle the OIS slightly to achieve the same effect.
It seems like movement would be effective for averaging out random noise, but the described process isn’t for eliminating random noise, it’s for eliminating persistent hotter pixels on the sensor.
Indeed, and in fact the pixel does exactly the same dark frame trick to identify hot pixels. I don't know that it takes as long though - perhaps it's hidden by the fact you can keep doing other things while the photo is processing.
Take lots of short exposures and fuse them. If the device is handheld you get variability in positioning for free, if it's on a tripod, it will automatically wiggle the OIS slightly to achieve the same effect.