The market just isn't mature enough yet. We are still in the volatile phase of crypto, it might honestly take years to go mainstream to the extent that it will support a freelancer platform.

Another issue is lack of escrow.

But really it's the same reason why there aren't so many other mature services for crypto.

Even though bitcoin is almost fully mined, it's still volatile.

Things will only change when the masses can easily get their hands on crypto and I don't mean via an online exchange.

It's a shame that there isn't a whale out there who could just give away say 100 bucks of bitcoin in some kind of postcode lottery. Not too much that people would use an exchange but enough that people will just spend it instead.