Bitcoin for example has appreciated significantly since last year till now, if one was to have loaned out their Bitcoin at the start of last year, it's not possible the interest will be close to the ROI they'll earn if they had held it. The risk is also definitely not worth it, just as storing coins in an exchange wallet is risky, so is loaning your crypto out.

If you're an investor, it's in your best interest to select coins that can appreciate in price overtime, you naturally make profit from such coins as time goes on and they appreciate, I'd most likely even think that if you want to consider loaning out any of your crypto, it should be shitcoins that you're really not sure of for the long term, and then again, such services wouldn't accept such cryptocurrencies.