The old API Explorer had 2 fold levels, IIRC. But the new one has only one. And also, all of them are unfolded when you open the page. So yeah, a lot of scrolling. I think I suggested a while ago to have the 2 fold levels in the new one too, but I do not know if it got to their backlog or not. Maybe @tim.smith can confirm
Also, if you did, it would be nice to have a setting to "have it all folded by default on start", like the old ones.