> My best guess is either low hardware

If there was other apps we use that had the same issue, I'd chalk it up to hardware too, but maybe they simply don't test it on representative hardware? That might explain it.

> they likely went with something HTML/CSS-based, which would explain the performance issues

Not sure, the web browser in the TV seems to handle things just fine, and much faster than Amazon's app, so I don't think HTML/CSS is to blame here. Probably shit architecture/software design, as usual.