Exactly. Android had a native stack and it also had terrible performance. I don’t think it was any worse than WebOS’s.
There’s good reason to blelieve that given enough time and even a fraction of resources that the Android team had WebOS would be able to significantly up their performance game (I say a fraction of resources because there is a lot of well funded open source development being done to improve web tech on mobile, through Chromium, WebKit and Firefox that would be leveraged).
But you do have to admit that UI latency on it was quite high compared to iOS. I mean, so was Android back then, but they improved it significantly.