It’s been a decade since Bo Burnham, then 16, uploaded a video of himself to a fairly new site called YouTube. He was singing a song about how his family thought he was gay.

After the video went viral and was seen by millions of viewers, he earned offers from Hollywood, a special on Comedy Central, a theater tour and a deal with Netflix. Bypassing the traditional route to stand-up success, Mr. Burnham grew into a boldly theatrical and formally clever comedian whose trailblazing career was a forceful defense of the internet as a comedy incubator. That’s why it’s startling that he has now emerged as one of its most scathing critics. It’s as if the monster turned on Frankenstein.

“If you look at original content on YouTube now, the center of it is all-caps comments and girls’ cleavage and commercial, derivative” videos aimed at “what 13-year-olds want rather than what they need,” Mr. Burnham said Monday night in a Williamsburg apartment where he’s staying while acting in a movie. “I don’t mean to sound fatherly, but it’s amazing to watch a medium sell out on steroids.”

Citing the work of the author Douglas Rushkoff, Mr. Burnham said that watching the proliferation of comedy online had made him appreciate the virtue of old-fashioned gatekeepers. “I don’t think democracy is a good thing always,” he said. “This world of Rotten Tomatoes and user ratings on Amazon makes for safe, homogeneous choices. It’s made me go: Studio executives aren’t that bad.”