Don't be embarrassed, LilacTree1 – you've put your finger on precisely the problem. Viz, why on earth would the Pensions Regulator need RIPA data?
If PR thought a crime was being committed, they could go to the police who would apply for a warrant – or at least need sign off by a designated senior police officer (I've lost track of who needs to sign off what these days). But no, the PR has been given the ability to dip its hand in the data just because... it would like it.
From the article I linked:
Why should the UK pensions watchdog be able to spy on your internet activities? Same reason as the Environment Agency and many more
www.theregister.co.uk/2020/04/23/uk_snoopers_charter_sequel/
And lastly, the Pensions Regulator, which checks that companies have added their employees to their pension schemes, need to be able to delve into anyone’s emails so it can “secure compliance and punish wrongdoing.”
Taken together, the requests reflect exactly what critics of the Investigatory Powers Act feared would happen: that a once-shocking power that was granted on the back of terrorism fears is being slowly extended to even the most obscure government agency for no reason other that it will make bureaucrats' lives easier.
None of the agencies would be required to apply for warrants to access people’s internet connection data, and they would be added to another 50-plus agencies that already have access, including the Food Standards Agency, Gambling Commission, and NHS Business Services Authority.