BTC, ETH, LTC, BCH are all DeFi tokens.
Be careful with saying wrong information like this as your account is also a high rank. You could mislead beginners here.
To correct you, they are all COINS who have their own individual blockchain.
Tokens, on the other hand, do not. They run on top of blockchains like Ethereum.
While the Ethereum blockchain is the most popular aming DeFis, some tokens run on other blockchains like Tron and Eos.
As to the question in the OP, I don't understand why would Paypal need to add tokens into their platform when they already have Eth.