Collateral --> 1) Physical Collateral --> Gold, Silver, Collectibles, Car, Bike, anything that has some value.
2) Digital Collateral --> Coins, Tokens, Accounts, Gift cards etc anything that can be sold Instantly in case of loan default.
Depends on lender whether he want to take it as collateral or not after analyzing risk involved with particular asset.
PayPal can't be sold in case of loan default, that is why it can't be consider as valid collateral.
Hope you are able to understand what I'm trying to say, and look for an alternative to get funded or provide something that can be sold.
Gift Cards are definitely not collateral. Nothing stops me from giving you the gift card, taking the BTC and using the code. Accounts are debatable but most accounts are recoverable too