I like the Mii TV 4k sticks. They run android tv and have the usual apps, or you can install your own launcher, apps (look into stremio!) and everything through downloader or adb. Then you can disable the bloatware through adb, theres a few lists online if you search. With a launcher manager app, mine loads straight to productivity launcher (I also like flauncher).

Do not try a firestick, theyre heavily locked down now.

I then just deleted the network on my smart tv so it can’t send anything. Along with my pihole, hopefully theres no telemetry getting out, although not checked it. Its impossible to find good TVs that aren’t smart anymore unfortunately, the data selling either subsidises the costs pricing out dumb TV’s, or more likely they make so much from the data selling that they only sell those.