All the rates are indicated on the thread of those bounties, so if it's about determining which pays higher. It's all written there and you've got to consider which type of your bounty going to join.
If it's about the success rate, it's far from 2016-2017 era where most of the bounties during that time have higher success rate and that's why it's lucrative for the bounty hunters joining a lot of bounties on those years.
This is true, most bounties today do not end up in exchanges.
The team will distribute your share after months and months, but you will be very lucky if they will have good value in the market.
From the countless bounties that are running today, you will only see few of them to hit in the market.
To minimize wasting your time from this bounty program, maybe look for btc paying campaign even if they are not paying high from your standards.
At least, you are very sure you will get paid at the end of each week. Because giving high rewards from bounty programs is not a thing anymore.