Outside of their initial showing, the Frightful Four have been the team the Wrecking Crew would make fun of. They'd make a halfway decent showing in part one of a story and then, basically the FF laughs at them until they self-destruct. Their fourth member has been a revolving door. the Sandman toys with good guy dom. The Trapster is totally out of his league, and the Wizard who might be able to compete, is dealing with a B-team at best.
But, damn, that run from 36-43 was truly epic for them. It is a shame they never managed to keep any of that gravitas. The U-foes are basically Red Ghost's Super Apes with hair cuts.