I think there is not a good bounty available at this time due to which most of the time those professional managers are offline. Moreover, most of the new projects at this time are dangerous because the number of scam projects is high due to which they consider it dangerous to manage the bounty. Also, it's not 2017 and that year was the best year for the crypto revolution, so all the bounties would have made a lot of money. At that time the amount of scam project was less so any manager could manage the bounty then.