Thank you guys.
I think It's important that we can collect a bigger list of devices that can run the HTML versions smoothly but can't run the APK properly, so their engineers can test on the actual device.
This was stated by a chromium project member, and probably not everyone is aware of:
"WebView's rendering pipeline is not the same as Chrome's and is likely to be slightly slower in general on any device. Because the way it renders is different, it may provoke different behaviours/optimisations/bugs/etc from GPU drivers as well, which may also affect performance. If we have a reproducible case where there's a large difference we can investigate further."
So, that could be the final explanation for the bad APKs performance, but like he said( and Artpunk too) their Pixel devices can run the APKs smoothly, so I think it's still relevant to collect the information about the devices that can't run the APK well so they figure out the performance difference.
And for me it's not that obvious why a Pixel device performance would be so much better than a medium-range Samsung Galaxy