It can be done, I think, but it has to be VERY well funded - you need to send salespeople / lobbyists to the various on- and offline shops selling TVs, you need "SEO experts" to try and beat the competition's "SEO experts" on the internet and e.g. Amazon's search results, and you need a legal team to help with the inevitable heap of lawsuits you'll get (patents, design infringement, etc). And then you'll have to deal with the competition pushing the prices of their devices below yours; Samsung can afford to sell TVs below market value for decades if need be, JUST to push out that shitty newcomer that does ad-free TVs, and they'll make money off of the ads + subscription services they offer in the meantime.
If they can pull it off for more sophisticated integrated solutions like phones, tablets and laptops, I'd have thought that a TV brand would be even easier.
Surely buying a commodity panel off of an existing OEM would negate a lot of the legal issues, and going DTC to the kinds of people who are specifically looking for a dumb TV is quite a decent niche to market to?
Usually I disagree about niche hardware in this way (for example, usual mentions about a similar approach for phones and laptops), but the dumb screen might just be dumb and cheap enough to make work at this limited scale?