The reduction in jobs in the gig economy has to be a direct result of the overall recovery of the economy. We are at a point where there are more jobs than workers to fill the jobs. Why would anyone take a crap gig job if they can get a steady paycheck? There are people that like the flexibility but the pay sux and no benefits for most of those jobs. The gig economy job is the new temp job. Just like temp jobs, they…
I think you're underestimating how important that flexibility is to a large contingent of people. I have talked a lot of Uber/Lyft drivers and have heard a ton of stories about how valuable that flexibility is. It's huge for students who are in school, for people who already work another job but want supplemental income, people who are mostly retired (or never worked) but have some new expense come up (one lady I spoke to recently started driving for Uber just to help pay for her daughter's upcoming wedding), people who are pursuing careers in music or other artistic endeavors, entrepreneurs who need a way to pay the rent while getting their business bootstrapped, etc.
For a lot of people in those situations, the control over their time really is a crucial aspect of what makes Uber/Lyft desirable.
Granted, that's just one aspect of the gig economy, but it seems to be a big one.