it seems they assisted gates with getting in touch with women to have an affair with

That’s not clear. Another possiblity is the Epstein traded some of his compromat for the information he used to blackmail Gates.

he’d be lying to Congress about this, a felony

A felony that’s seldom and very selectively prosecuted.

If they have evidence of gates lying, he’d still be known as a pedo, and ending up a criminal as well.

He might be a more useful asset out of jail than in.