Not something I would install to my grandma. Really, she doesn't of course have internet, just the old analog landline phones, doesn't know how to use a computer or a smartphone or anything like that, I want a TV that is simple, just press a button and it powers up on the specified channel.

Next year they will switch off DVB to migrate to DVB-T2, and of course I must buy her a new TV (using a decoder it's not an option, too complex having to manage two remotes controls), and it seems that nobody produces dumb TVs anymore...

Yea a monitor is not a bad idea but they don't come in very large sizes or are way overpriced. Also if you'd want a decent speaker build in, monitors are not always the best

Look into conference room monitors they run around 1k USD and typically are available for reasonable tv Sizes. I think the Dell ones are Up to 55 inch

or a videoprojector. JVC videoprojectors are really great, extremely high image quality and are dumb :)