What's wrong with Apple TV? It runs VLC if you want to stream something from your NAS.

I tried to look at setting up an stripped down privacy-focused Android based box for Netflix, but ran into issues. Seems like you need to be spied on to run Netflix.

I tried going that route, but most apps for streaming are Android. And that was only one of the issues.

It was a rabbit hole and in the end I got back using my NVIDIA Shield. This is about 10 years now, but it’s actually still the best option.