It's not. It is an electronic money institution, which is far from a bank, it can only keep customer funds and process payments.
> PayPal (Europe) S.à r.l. et Cie, S.C.A. is a credit institution (or bank) authorised and supervised by Luxembourg’s financial regulator, the Commission de Surveillance du Secteur Financier (or CSSF). CSSF’s registered office: 283, route d’Arlon, L-1150 Luxembourg.
Can't comment re PayPal specifically.
Paypal and revolut are 100% not banks, they are financial institutions or emis, They can manage your money but not lend out anything and they have to hold the assets at 3rd party banks.