UpWork has a market cap of near 1bn and yet no one in the recent years has made any significant attempt to compete with them. Of course they have huge network effect and they dominate the SEO, but if executed well then the potential winnings are huge too. A startup with 5-10M investment could grab a significant share of the market.
You have of course freelancer.com, but it has a terrible reputation and it is mostly used by low skill workers.
You have fiverr.com, but their unfortunate branding has stagnated their growth outside of one of gigs.
You have toptal.com, but they specialise in high-end talent contracts.
UpWork has a sweet spot of mixed calibre talent of all sorts and no clear competitor.
Thoughts?