For most people it has probably something to do with Search Engine Optimisation (SEO), but…
Tutorial: How to Use PayPal via Google Pay on YouTube, Gmail, and Google Play
You can already use your PayPal account to make purchases through Google Pay. Now, Google and PayPal are extending their partnership to allow you to use your PayPal account to pay for things across the Google ecosystem, including Gmail, YouTube, and the Google Store. Better yet, if you link your PayPal account to Google Pay, you won’t have to keep signing in to PayPal every time you want to make a transaction.
— Leer en lifehacker-com.cdn.ampproject.org/c/s/lifehacker.com/how-to-use-paypal-via-google-pay-on-youtube-gmail-and-1826325622/amp