investments have always been the best option for passive income, real estate, stocks, cryptocurrency, you choose yourself when you evaluate the market, your risks and information from other people and sources, the choice is always yours
Passive income does exist but not in all sides, because in cryptocurrency it is very difficult to find passive income except through Staking where everyone has to provide their capital first, so don't chase passive income but chase income that is always there even if it's not positive.