I would start with selling 50" and 65" inch "dumb" TVs. Just the panel, a nice enclosure and a board with an IR receiver, TV tuner and HDMI outputs. BYO top box and Soundbar. I wonder how fast it would take to get 10000 orders.
See the LG 48 CX OLED television versus the Gigabyte AORUS FO48U OLED monitor. The LG was a jump in quality and performance (4K 120Hz) and many people bought it to use as a computer monitor. But it's smart (cannot disable advertising itself over Bluetooth while on), cannot be woken up over HDMI (requires using the remote control to turn on each day) and it does not have displayport in.
The Aorus is the same panel but not a TV, functions as a monitor should, and I would have bought that instead had I known.
If a product finder like alternativeto.net existed, where you find non-shittified alternatives to a popular appliance, I would use it every time I shop.