Check out this video and note that a new Hellcat makes 707hp (SAE net, not SAE gross) on catalytic converters. I think when you see how far cats have evolved, what benefit they give, it's real easy to love them even if you are a performance junkie.
I always go back to the Hellcat's 707hp when people with not-racing cars talk about removing their cats, because odds are they will never make enough power for cats to be a restriction. My last such argument was the most obvious: with a guy with a 150hp Lincoln Town Car, and I had to apologize for laughing when he said he was gonna remove the cats so it will go faster. (owner is a nice guy, just unaware of other issues like a 50mm throttle body, 14 lb/hr injectors, and terrible heads/cam that make his plan impossible.)
And if you have an older vehicle with 2-way or early 3-way cats, just upgrading to an off-the-shelf modern cat will outflow your engine for years to come. Tell me what you think of this!