Design Agency Huge did research on scrolling:

We wanted to know how page design impacts these user behaviors and to what extent visual cues help users scroll below the fold.

To find out, we conducted user testing with 48 participants over 3 days. We did so using unmoderated remote testing to see how this less conventional methodology would compare to mediated testing, our usual approach.
Spoiler: Everyone scrolls.
I’ve been designing websites for 15 years and I’m fucking sick of the fucking “fold”.
I can’t want until “the fold” becomes a non-issue and we can stop talking about it.