I got the Lenovo Tab M10 Plus 3rd Gen three or so years ago for watching movies when away. There was almost no crap pre installed, and what remained I could uninstall.
Av1 and vp9 usually works, there is the occasional file that acts weird. Hevc, whatever the bit depth, resolution or encoding method works flawlessly.
It has a Qualcomm SDM680 processor, it's also available with a less powerful one, but the one I mentioned has definitely enough power to play 4k 10bit TrueHD whatever.