The fact that there is basically no good "premium" options for smart devices, just cheap adware trash or more diy type stuff with home assistant and the like, tells me there is not much of a mainstream market for most of these devices to begin with. If your only niche is just the hobby crowd or shit that has to be so cheap that you can't make a profit without riddling it with ads then it might not be a market worth getting into.
I'm converting from Firesticks once the new Apple TVs come out. I'm sick of the constant upselling and Amazon's been putting much more effort into blocking me from using a custom launcher than basic stability and usability.