TBF, many people don't have that Home key. I agree with you, though - there should be a better solution. At the very least, just have an optional "Top of page" toolbar button in your browser.
That's one option. On macOS, it's fn + Left. On Android, I'm not sure there's anything.
On Android I think the typical interaction if to "fling" the page downward which will rapidly scroll until you crash into the top. Seems adequate for all but the longest pages.