There are really not that many that gives a decent amount of return compared to the volatility of crypto price swings however the only reasonable explanation would be that "might as well" is a logic while getting extra money. I mean if you are going to get a coin and that coin goes up or down, you might as well select a coin that will be staked and give you a some free money.

Also, for staking purposes in exchanges if you give certain amount of your coin there and than they have your money, they basically have insane amount of it enough to call it a profit while it exists. Think about how much dash binance probably has, they are allowing you to trade it on number but as long as you do not withdraw dash from it you are just allowing them masternode it and so forth.