Bounty campaigns have not lost their importance for the cryptocurrency market, only the cryptocurrency market has lost interest of investors. It is because of many projects that collapsed because of the long-lasting bear market, and because of the many scammers that have appeared, investors stopt to be interested in the ICO market. When the bear market ends and the cryptocurrency market stabilizes, the bounty will be popular again. It's just a matter of time.
And to add here, bounty campaigns which are paying either eth or btc are the only ones worth participating for. Most if not all, token paying campaigns have lost the interest of many because there is no assurance that you will get paid if ever you get paid, and the tokens they are paying have no real value. Though there are still users who are joining those campaigns, yet, they know that there is a chance that they will not get anything of value in return.