IMO none of those are as easy to care for as stainless but many people on here like cast iron , when i was a kid we had cast iron and my Mom swore at it most days it just never looked clean but it might have been a different finish than what is available now.

I don't know about that kind of sink, but I just got rid of two Kohler white cast iron sinks in favor of stainless steel during my kitchen remodel. I could never keep my cast iron looking clean... I never seemed to have enough elbow grease. My hubby was always able to get it clean with bar keepers friend, but no matter how I tried I didn't have the strength. (I have fibromyalgia and other autoimmune issues and hand/finger strength is sorely lacking for me.) Now the only thing I have to do is dry the sinks out if I don't want the water spots, otherwise they're super easy to clean for me.
Anyways, hope my experience with the cast iron is informative and helpful for you.