I'm just one guy, but I used Fiverr freelance services three times within the past year.
So I'm not making anyone rich. But I assume I'm not the only person who finds it all very useful.
There are some niches that I think they are trying to be "too" professional with (meaning, some tack on fees for things that are a bit too far beyond the person's actual professional level, or the gig purpose itself). But you can simply bypass those users anyway.
Upwork freelancers should answer too, thanks.
I used Fiverr this year for civil engineering and got scammed, but I did get my money back.