Congressional (and most government) committees are about as useful as teats on a boar. Their sole purpose seems to be as a signal to donors to direct funds (bribes) toward the right elected jerk. CongressCritter Blowhard is on the Energy Committee and I have energy interests, so I donate to Blowhard’s campaign.
Nunes, Jordan and a few others have been doing good work, working with Trump and exposing the corruption. They are giving Trump reason to fire Mueller, Rosenstein, and a bunch of other Deep Staters.
However, they still have used their power to make arrests for anybody in contempt.