You are unlikely to find a new non-smart TV... the TV manufacturers get kickbacks from the streaming services for bundling their apps.

If you did find one, it would be more expensive than the dumb TV because you don't have a bunch of streaming services subsidizing the price of the TV for you.

A computer monitor may work for you, or just buy a smart TV and never connect it to a network. You should be able to set it to automatically start up on the last-used input so you never see the built-in UI.