The ones that I've caught have fought very well even on heavy gear
Compared to? I've seen all the Matt Hayes videos - Ebro, Soane, etc. For 30lb-100lb fish, they don't fight. A 30lb yellow-fin tuna. That's a fish that fights. Or a 10lb steelhead, or a 5lb mullet - if they got to 30lb, you'd need a boat road and 200lb line to stand a chance.
Catfish - the piscine equivalent of Chris Moyles