Generate a html table (don't use html tables) with 500.000 x 500.000 elements containing short random strings. Put an element on the page that is locked to vertical and horizontal scrolling. Scroll away and watch the difference in FF and Chrome (both browser will have difficulties but one of them is usable).

Why throw that away? I heavily disagree that one rendering engine would be preferable.

I really like to use Chrome but it is opinionated. Bad image quality for scaled images for example. Do not like.

I am no web developer, I think someone could give you more details.