No you don't. At least not even on old IE 11, and I can't imagine any other browser doing it worse (and I know Firefox). The browser is supposed to allow you to access the site my just confirming that you want. No root certificates.
I used mobile Safari both on iOS 11 and iOS 10 with no problem on that site. Also on mac OS, at least according to this picture, it's not the CA that's accepted, just the exact site certificate and only for the given site: