Being a manager is far better than doing bounties, when in terms of work the manager has the easiest job and when it comes in payment the manager has the highest amount that will get.
I dont understand what makes you think that managing job is easy. It takes hours and time for a manager to check everything and update the spreadsheet. And dont think managers are highly payed for doing this. I know many who does this job for few tokens.
This field is very competitive nowadays. So to get the job, many bounty managers offer their service for tokens.