The study was an internet survey with no verification and they mixed the data between a wide variety of types of remote gigs, including upwork and fiverr and the further mixed the idea of “waiting for work” which falsely decreased the average wage.
The lack of empathy of some commenters here is truly shocking.
If you're on a contract that pays by the job, you're back on your own time as soon as the work is done. You got paid to give someone a ride, they get out of your car and the contract is over. You can go do whatever you want. But you don't get paid any more until you do more work. That's the nature of it. There are people who voluntarily choose this when alternatives are available, because they value the flexibility etc.
I have to imagine Europe has food service workers and cashiers and cleaning staff and other jobs that nobody really likes to do and that don't pay particularly well, but that aren't hard jobs to get. So if the gig work is actually worse instead of better, why are they choosing it over any of those other things which are still available?