I can now go to a vendor's website (say jrwatkins.com, etc.) on my phone, checkout, do a fingerprint/face scan on Apple Pay and the transaction is done in under 5 seconds.
I assume the experience with Google Pay is similar.
There's no longer a need to create an account on the website. The delivery address defaults to the one on Apple Pay (and can be modified at time of payment). Delivery method can also be selected on the Apple Pay screen. My credit card number is never transmitted. This type of frictionless checkout that was once the domain of companies like Hoteltonight is now becoming more common on ecommerce sites.
I don't know what payment methods these services require now, but in the beginning at least, they both supports just credit cards, which is basically suicidal. Most users won't be able to use it at all.
From merchants' perspective, they don't need to pay for transactions on WeChat Pay or AliPay, whereas both Apple Pay and credit card companies would charge them for usage. For this reason most small business wouldn't even think of using them.
According to the Apple developer docs[1], websites don't have to integrate with Apple Pay specifically; Safari also supports the (fairly new) platform-neutral Payment Request API[2]. Google's docs[3] suggest that something similar is available for Chrome on Android.
1. https://developer.apple.com/documentation/apple_pay_on_the_w...
It supports Apple Cash, which in turn can funded via a bank debit card. (kind of like Venmo). There's no transaction fee with Apple Cash.
I believe there are currently no additional fees on the merchant side to accept Apple Pay [1], unless the customer uses a credit card via Apple Pay in which case the standard credit card fees apply.
We've never been big on mobile payments in the U.S. (because credit cards), but I'm finding myself using Apple Pay more and more. I read somewhere than ~50% of payments in the U.S. are now contactless.