If you are open to projectors they still make “home cinema” projectors that don’t have any smart features or connect to the internet.
I have a BenQ (710tki iirc) that is like this and I believe it meets all your stated requirements (size, resolution, etc). I’ve been very happy with it.
This is what I landed on as well - projector connected to an Apple TV. It cost a bit more, and there’s some extra setup, but the results are excellent.
The main issue switching to a projector is figuring out where you are going to position it (different projectors have different throw distances).
More money and more setup, but very worthwhile in the end IMO.