Quibi launched in April 2020. TikTok by this point would have 2 billion downloads [1]. It's difficult to assess they were trailblazers here. I might even say a component of their failure is free mobile video was widely accessible by this point.

[1]: https://www.theverge.com/2020/4/29/21241788/tiktok-app-downl...

Was that at all like TikTok? I thought it was professional creators, not community-sourced.

Didn't have every aspect nailed? Definitely trailblazers? Quibi is a prime example of an absolute business wipeout. They got a bunch of investor money together, showed no interest in what viewers actually want, and then went down in flames immediately upon public release of the product. The whole thing was a disaster that didn't accomplish anything beyond putting a bunch of capital in the pockets of C grade C suite players.