what kind of launchpads are you referring to? WOuld be interested to check them out?
Some project do that, and some project not.
Most of the bounty during the time 2017-2018 are being maximized for the salesmen/successful of their token selling. However, since right now most the token offering is using launchpad or exchange.
Project are not quite active anymore to launch bounty in here, since almost 90% of token offering using a launchpad always sold out more than 80-90%.