Just visited my favorite coffee shop near my uni, and they launched a loyalty program with a 5% cash back. I decided to register, opened the website, entered fake personal info, and the following screen met me:
Loyalty card
%NAME%, your loyalty card is available via this link:
[ Google Pay | Save on your phone ]
That's it. I got confused, as I don't have Google Pay on this phone. But as there were no other links or buttons, I decided to tap it and see what happens.
Google Pay app showed up out of nowhere. Registered a loyalty card in my Google account. Showed me my fake name, loyalty points balance, and card's QR code. Showed all other loyalty cards I had on my Google account. Invited me to enter my card details and start paying with Google pay.
In disbelief, I closed Google Pay and tried to open it up manually. Maybe I just didn't remember installing it on my GrapheneOS? But I couldn't find it in my launcher. There was no Google Pay.
There was literally no Google Pay.
There was a sandboxed com.google.android.gms (Google Play Services) which turns out to have the entire Google Pay app JUST FOR THIS DAMN SITUATION.
I can't open it myself. Google Services settings suggest me to install it, but it is already installed just in case I have to add a loyalty card. But if you go further in Google Services settings and open the Google Pay settings, it just opens Google Pay. So to use a loyalty card I have to do 7 taps. And all this time I was using another phone with Google Pay installed just to use another loyalty card I always forget (which uses Google Pay API too).