Bounties are good but i think it gives us rewards after a long period on the other hand trading gives us instantly but i think do trading with enough knowledge about market.
So from that people prefer to do work in the bounty even for a long period of time. At least they are doing the best for now. I think trade is certainly profitable but basically the risks in trading are very high. So if people aren't ready to trade, of course they aren't recommended there.
Indeed, bounties require a long period to make them but they are also not risky in case of money investing. Therefore, bounties are really good choice for those one who are not ready to take a risk.