[edit: To be clear, I assume the part that OP is not sure if it’s satire or not is “or switching to a more privacy-conscious browser such as Google Chrome.”] The emphasis in
Firefox is worse than Chrome
is in the original. To me that clearly implies that they are of the opinion that in general Google & Chrome are worse on privacy than Mozilla & Firefox. The comment at the end is just tongue in cheek snark alluding to the fact that in this particular case google did better for privacy in Chrome than Mozilla in Firefox.
or switching to a more privacy-conscious browser such as Google Chrome.
I’ve just said “I don’t have one” when asked this for awhile. This never seems the phase the cashiers, I’m guessing they know what that really means. Half the time I still get whatever discount, though I’ve never tried to sign up for a membership saying that.
If it’s an online form my phone number is just (local area code)555–5555. I’ve never had that not take, except for one case where it automatically enabled 2-factor auth and I had to create a new account.