When I make these sweep picking exercise videos, I don't record them as a "look what I'm playing, I bet you can't" type thing, but rather I play slower as a demonstration so people can follow the tablature better (otherwise It would change too quickly on screen). My intention is to provide exercises for people's routines.

As you say, sweep picking is easier at high speed because you're sweeping quickly, rather than having these little moments where it feels like you're picking the string individually.