That's only allowed if the destination is a "seller", and the debit card is tied to a bank account. You can't send to random pre-paid credit cards. That would be the scammer's dream.
Also, Stripe transfers funds to recipients only once a day at best. For many accounts, it's once a week. (This is also true of Venmo, but they hide it from you in the app. Send some money to a nearly empty account with Venmo and then try to spend that money, and it becomes clear that Venmo's immediacy is an illusion.)
In the US that's true. Here in 21st century Britain I can initiate a bank transfer to another person from my phone, and they can immediately spend that money.
In fact, for much of the world, this "deposit a check" is definitely from last century. Instant transfer is reality in Europe, and even many countries in Africa and Asia operate mobile banking services where transfers happen right away.
The currency is not necessarily cryptocurrency; it can be "air-time".
Here is a dirty little trick to make sure your check appears instantly in your account -- first you cash the check, then you deposit that cash to your account.
Also, Stripe transfers funds to recipients only once a day at best. For many accounts, it's once a week. (This is also true of Venmo, but they hide it from you in the app. Send some money to a nearly empty account with Venmo and then try to spend that money, and it becomes clear that Venmo's immediacy is an illusion.)