The point of RIPA is not to allow surveillance, but to disallow most of the surveillance that was being carried out unless clear proceedures were followed.

RIPA wasn't a snoopers charter, it was designed to limit the amount of snooping that was happening and to bring it under some kind of regulatory framework.

It's not a very good law, and it's too generous to people wishing to carry out surveillance. But it's better than the uncontrolled surveillance that was happening before.