Unpopular opinion time;
Most of the new projects, if they have USD(T,C,X) to spend on advertising, will do just that, pay for advertising, be it Google, Facebook, Youtube, etc... Some will even go to renowned crypto advertising sites and pay for a real service. Lets be honest, conversion rate of bounty is less than 0.1%.
However, if they pay with tokens, then they're basically taking a gamble, where no matter the outcome, they're winning in that particular instance. What i mean is, if the project is a success, they will give coins/tokens which are "generated" money, and if the project fails, then they haven't had paid anything themselves tbh.
So, no, except for some limited participant highly targeted bounties, i don't see ICO's paying stable coins, or even tradable assets as bounty rewards.
Coming from an experienced bounty campaign manager, I think there is no reason not to believe you, so yes I agree with you as definitely that's the reality here, both gambles, the team and the bounty hunters as they both exert an effort to try to make a project successful.
maybe we can say that the success rate now is very small, probably 1%? or even lower?