Would you suppose that the failure of their IPOs points more at the lack of a bubble? I mean to suggest that in a bubble / "irrational exuberance", these IPOs would be more likely to succeed, and after, the value of their public stock would go up dramatically because investors were being overly optimistic and speculative about these companies. Instead investors determined they were overvalued prior to even entering the public market. To me, the failures indicate the lack of a bubble.
Although I wonder about the bubble-iness of the gig economy. I've had increasingly bad experiences with it (more on the side of a customer), and I assume workers have worse experiences. I 'feel' like something's got to give at some point, where you'll see over some short period of time, a ton of people just begin to opt out from the "gig" economy on both sides (as customers and workers), aside from the fact that many workers depend on it.