I used to use it but when I left it was ... adjusting into showing me nothing but furry, and also porn artists so I wasn't in the mood. I also saw no note or way to grow unlike on say Twitch where you can get at least some ad revenue. Picarto seemed entirely set up so that if you wanted any income you needed to get it from Patreon (another site that's known for nudes and porn art).
I also recall it locked your resolution to stream at in a LQ number (like 360p or 480p) unless you did a paid version or something? Something that Livestream at the time didn't do, and only locked your resolution lower if you got over 50 viewers or something odd. Livestream was odd. Again, something else that Twitch doesn't do and instead a viewer can change themselves what they're viewing at.
(one more note on quality)
I just remembered the site loaded /buffered horribly for me compared to LS or twitch. Twitch at the time was also bad, but it's improved over time and only infrequently has issues -which is all on Twitch's server side if not the streamer's internet directly. Otherwise, the few times I've poked at Picarto recently it's always a huge lag fest and just isn't fun to sit on. Doesn't matter what browser I use either, or cache, or number of tabs. So strictly as a viewer, I cannot say my experience there was fun. As a streamer, was a ghost town.