https://wccftech.com/deeper-paypal-integration-with-all-google-services-in-the-works/

Despite its popularity, PayPal integration across several services is a bit wonky. Samsung Pay added PayPal to the list of payment options almost a year after they said they would, while Android Pay (now Google Pay) did the same last year. However, one still couldn’t pay using PayPal without going through a dozen hoops, and as of today, that is set to change. Soon, you’ll be able to use your PayPal account for purchases across all products including YouTube, Play Store, Google Pay etc. According to PayPal’s latest blog post:

Today, we’re extending that partnership to deliver more seamless payment experiences across the Google ecosystem. Soon, users in the U.S. who add PayPal to any one of Google’s services will be able to pay across the Google ecosystem, anywhere that PayPal is offered as a payment method, with only minimal setup.