The website works on the Safari that comes with the latest OS. I can't update the Safari version without updating the OS with a 14GB update. Nevermind the extremely annoying hassle of having to backup the devices before the updates "just in case".

I don't have to do that for any non-Apple browser while using the same Apple laptop. [0]

I think it was the late and great Joe Armstrong who said, in a tongue-in-cheek remark on object oriented programming,

"You want a banana, but to get the banana you need the gorilla holding the banana and the [goddamn] rain forest it lives in." (brackets might be my frustrated addition.)

[0] there were other websites that would work seamlessly on other browsers but would throw security errors that disappeared after the OS update, including an email provider that is regular posted about on HN.