> If you insist on giving me a fake email, your business is probably a liability I don't want anyway
It's not a fake e-mail, it's a legitimate e-mail that you can send e-mail to and the user will receive, which has to be created by a paying iCloud user and not an anonymous rando off the internet.
I'd be interested to know what downsides, if any, you see for a website to accept a private e-mail address like this. Do you have a legitimate complaint about these sorts of e-mails? Again, given that private relay isn't an 'anonymous e-mail service' (it's still tied to your iCloud account so spam, etc. shouldn't be any more of an issue) but merely an 'anonymous to the person you're giving the e-mail to' service.
If your actual complaint is 'if you insist on giving me an e-mail that you can revoke unilaterally making me unable to contact you against your wishes, and which cannot be associated with other user data from other sources to build a profile of you, then you're not worth having as a customer' then that's a separate complaint - and one that means I want nothing to do with your website.
I'm curious what you think the difference is between "a paying iCloud user" and "an anonymous rando off the internet." How many Apple gift cards do you reckon get sent to fraudsters every day? Decades worth of iCloud+ surely.
I'm running a business where I need to know who you are, because my platform can be used defraud other people. If you're trying to hide who you are from our very first interaction, that's a massive red flag.
If you can trivially create hundreds of these emails, and fill in the rest of the required info with bought/stolen/generated PII, now I have a vector for mass fraud. Requiring you to use a recognized non-anonymized provider doesn't stop you, but it sure does slow you down. (It's not this simple of course, but all security works in layers)
If these terms are not acceptable to you, then great! Don't use the website, there's no need to be salty because that's what you said you wanted. Isn't it?
I don't mind either, because the number of legitimate users who are bothered by this restriction is infinitesimal compared to the number of fraudsters who would take advantage if it wasn't in place. It can be difficult to comprehend the scale of platform fraud unless you've worked in this area, many days fraudulent signups outnumber legitimate ones.