Very few bounty managers are still in demand by bounty hunters, and to become a successful bounty manager is not easy now, because most projects now are not as successful as in 2018, which effect makes managers lose the trust of bounty hunters or project owners/developers Meanwhile, the leading bounty managers who are paid with BTC are in a different context, because what I know is that usually those who pay using BTC are in service campaigns.
In 2018 there were not many successful bounty campaigns, even if there were only a few, you can check this again because a very gloomy period in the crypto space occurred in 2018 which could then improve again in 2019 and 2020 during the pandemic.
And for a campaign that pays BTC in the service section, I don't think it can be equated with a bounty because the payout is weekly for all participants.