Get a Pi sbc of some sort, install an OS you trust, run Kodi on it, and only ever use the TV to display that.
Streaming services, YouTube etc, are available as Kodi addons. Though it's a bit of a hassle to do l the first log in to your YT account, these days.
Never use the "smart" features of a TV, which are basically data harvesting to subsidise the cost. Never ever tell your TV the wifi password.
Works for me!