I believe that investors of Polkadot ICO where the very lucky investors since the ICO was launched few years ago. How i wish that there's a bounty for this project but i found nothing except for their bug bounty that is far beyond my skills. With a project such this that is well funded and with so much hype, i can only hope less for them to offer bounties like i used to participate in this platform.
Polkadot don't find any interest in bounty campaign that's why they never introduced any but there are big projects like Polkadot that did introduced bounty campaigns, you just need to be active and watch out for new bounties, we have seen Ferrum, Cartesi and DIA, they are big until this day