If the project issues the debit card themselves then that is a good feature. Being able to liquidate tokens or altcoins anytime through the debit card will reduce transaction time and fees when it will not pass any local crypto exchanger anymore especially if the local crypto exchanger accepts BTC or ETH only.
May I ask which currencies in addition to BTC and ETH would you like to liquidate through a card?
Like I said, if the project issues their own debit card for their tokens, that is a good feature. So, that means whatever currencies that offer their own debit card is OK.