People want a decent TV. They want the alphabet soup 4K UHD OLED QLED etc. They want to be able to pick the size of the TV. And they don't want their TV to spy on them or show them additional advertisements.
My experience with digital sign TVs is they are much more expensive than the equivalent TV. They add on small business tools to display advertisements and in some cases still come with "smart" features. You generally can't get them in a big box store either.
When I bought my "dumb" TV I couldn't get all the features I wanted and I couldn't get one larger than 45".
The jist is that adding and cheap computer to the TV subsidizes it by allowing unlimited data mining and advertising opportunities for the manufacturer. There is little incentive for any company to cater to the crowd that doesn't appreciate this trade-off.