I mostly use carbon steel. But putting on my cooking nerd hat, there's one situation where I pull out cast iron, because it's annoyingly heavy:

It has more thermal momentum, thus when I am pulling stuff out of my sous vide cooker, it's better at quickly adding char (because the temperature drops less than in carbon steel or anything else).

(The only other reason I use cast iron is for the cases where the pan size is just more practical than my carbon steel pans.)

I will admit that I'm conflicted by this since there's also a distinctive way that my 3.5 kW induction wok cooker chars stuff in a very limited amount of time, but that involves me removing the smoke detectors from my kitchen and the two rooms adjacent.