PayPal is a payment system while Bitcoin is a currency. You might ask could Bitpay overtake PayPal.
Bitcoin is both a (crypto)currency, and a payment system/network. It isn't overtaking Paypal in real world use anytime soon.
Agreed! Bitcoin is a currency, yes, but it also processes its very own transactions because it has a network of its own. And so when someone asks whether Bitcoin will probably overtake PayPal, one must not refer to Bitcoin the currency but Bitcoin the network. If one meant Bitcoin the currency, he should have compared it to USD for example and not PayPal in the first place.
Well, AFAIK Bitcoin block size is limited to 1MB resulting to a rate of 7 TPS. PayPal, on the other hand, has a rate of more than a hundred TPS, processing tens of millions in daily transactions.