Paypal is a different type of payment option. If I pay via paypal my details are hidden from the store.

If I type in my credit card on the site they might use stripe or evopay or something else I wouldn't know either way. My details are save on the site.

On digitalocean you can pay via credit card or paypal. If you pay via credit card they take money out for service automatically. If you use paypal you manually buy the amount if credit you wish.

Different markets...

Stripe blocks some people who then have to use PayPal, also PP has been around for 20 years and expanded beyond payments, like what Stripe will be doing going forward.