On a related note, this is not about getting scammed, but more about getting the work you need completed.
I have had very poor results using people who have a full-time job and are trying out freelancing as a side gig. They rarely seem to be able complete the work on time, and of the quality you desire.
It's never due to a lack of technical skill. It's in part because they seem to lack time and energy to do the work after grinding it out all day at full time job. But more importantly, they seem to lack the time-management, and communication skills to manage the work.
An experienced freelancer can juggle multiple projects, but someone coming from a single-focus, full-time job often cannot.
I think this is why a lot of people dabble in freelancing, fail and go back to full-time work.
Edit: This is more a general note, and not about Upwork specifically, but the same definitely applies.
I think that was part of Apple's rationale, that is was all coupled together. I assume that’s not the case here?