Sadly most of these startups could do much better by just hiring and using human staff to provide the same services.
The business model "use low-paid labor to service wealthy clients" seems a little more inherently stable than that. In most cases, nobody expects a collapse. Why in speech-to-text?
This is a new take on the "value added reseller" business model. (I don't know what else to call it. Multi-level marketing?)
For instance, Autodesk's dealer channel covered the costs of marketing, sales, technical support, training, etc. While they kept the sweet nectar of profits for themselves.
"franchising" ?
With an internet based service, if you allow new people to sign up at any time and you become popular and you are not able to scale then you will not be able to service all of your users quickly enough. The people that you have pretending to be AI will be a bottleneck that makes it difficult to scale because you won’t be able to find more people suitable for that job and train them for it quickly enough. Then the business collapses.