"Cryptocurrency is slower than card networks." - not really, on a per-transaction basis. If you buy something at a store with a credit card, it takes weeks to get the money. With Bitcoin, you can spend the money in an hour. For small transactions, there's generally no need to wait past the point that the transaction is broadcast; and for online transactions it's not inconvenient to wait an hour before providing the product.
(of course, overall throughput is still atrocious)
(of course, overall throughput is still atrocious)