I assume that’s why the original argument is that it’s not been a net positive. I.e. the assumption is that lots of work can be good and necessary, while even more that is evil and excessive can end up with a net negative.
Anticorruption work is good and necessary. If the FBI's work was any good, they would be investigating the funding of the destruction of the White House, or AIPAC and Qatari influence in DC, not Comey and Obama. Right now, they are working for Evil.
Or the Trump coin crypto rugpull and money laundering scheme. Or the open insider trading. Or the $400 million jet "gifted" from Qatar. This year has been one grift after another.
The FBI's anticorruption work is good and necessary.