I recently bought a new "smart" TV --- but only after confirming that my selected model could be operated in "dumb" mode without any network connection.
From all of them I’ve used, ironically enough, Roku TVs are probably the best for operating without a network connection and don’t have any unremovable networked apps that pollute the screen. They just get much worse once you connect them, but they’re also easy to factory reset.
I bought a Hisense QLED model and run it in "store mode" so it acts like nothing more than a dumb display. A connected PC provides the "smarts" that I can control.