This is for websites - “card not present” transactions. You have always had to share that information when using credit cards when your card isn’t present.
No one is arguing that web merchants should accept cash. The commenter I replied to was referring to in person transactions
I don't know where you are carving out an exception. The entire page is about what happens with Apple Pay. It doesn't say anything about "card not present"
Further, the response is about a restaurant that has a website you have to use. The website offers Apple Pay as an option. If you pick it your email will be shared. It says so on the page itself.
No one is arguing that web merchants should accept cash. The commenter I replied to was referring to in person transactions