Only professional managers currently use escrow, the rest no one uses escrow and in fact there have been many threads discussing this but the evidence is that until now there are still many bounties that can be said 80% don't pay hunters
It's still much better than 2 years ago when maybe 1 out of 100 bounty campaigns was escrowed which shows it's going the right way. We could call it progress.
In time when people discover that escrowed campaigns don't scam they'll fight for a spot in one and the other campaigns will get the leftovers.
Of course it doesn't mean 100% will be escrowed at some point. There will always be people willing to risk it and work for an unescrowed campaign and there will be people with bad reputation who will never find a spot in one of those good campaigns.