Eh when you deposit money with a teller, it gets added to your account, which is in physical terms probably just a big storage and a database who has how much.
But in the case of debit card, the card ties the money to your account. It is actually that.
It's as if someone would steal from a personal safe at the bank.
Except that you have strong statutory rights and commercial agreements between your bank and the card networks making it very likely that you’ll be made whole.