2. can download netflix shows

Downloading is not an available feature of the AndroidTV Netflix app.

Only Google Certified and Netflix Approved device can stream HD or 4K Netflix, ones from this list:

https://www.reddit.com/r/AndroidTV/comments/cguehm/androidtv_device_comparison_table/

The Amazon FireTV Stick 4K is a great device for Netflix as well especially if you specifically have an older Dolby Digital - only audio receiver.

It can give you 5.1 audio from Netflix with older audio equiptment. None of the Android TV devices can.

Xiaomi Mi Box S

Most mecool km3 or km9 pro deluxe can do Netflix HD with a work around using 2 apps but it appears to be hit or miss if your box will do it from what I've read the KM9 Pro is more likely to work as not seen anyone with one that it didn't work for I know mine does but again for how long I don't know, Netflix need to be less picky about their partners as both the mecool km3 and km9 pro are Google certified and have Google widevine L1 drm, but still no downloads tho.

Netflix downloading is only available on mobile devices or Android boxes that aren't androidtv.

I don't think most Android boxes have the proper certification for HD Netflix.

A box that runs the Android TV operating system will absolutely have the required certification.

Note that those two sentences above are talking about different products.