I think that's a bit naive. In the micro, one new task economy startup might be a net gain, all other things being equal, but if it's part of a macro trend where skilled jobs are disappearing and being replaced with commodity task work, we might be sliding down a dangerous slope. Your final question sound kind of like the slightly more extreme argument that yacht factories enrich otherwise unemployed people. To me, that argument always rang hollow because how much wealth is really being transferred when demand for such things is fundamentally limited. I think ideally you want a broad base of jobs that can actually provide people with a middle class livelihood.
In addition to all this, let's be clear. The only wealth being "transferred" here is that of the minimum wage to workers. Everything else is making someone else rich, likely already rich investors.