Another fan of granite counters and undermount SS single sink.
I recently replaced a large section of the kitchen counter and eliminated a second level that functioned as a serving counter. By eliminating the backsplash and overhang, I gained more front to back space for the sink.
The 19 year old SS sink was still completely fine but it had always been too small, so I went for the largest sink that would fit in the cabinet, gaining inches in every direction, including depth.
Well…what I did not consider, as it was never an issue with the last sink, is that the sink needs to be pitched, if that is the correct term. (The way my walk-in shower is pitched so that the water flows to the drain hole on the floor.) So while this new sink is lovely (see link below), food residue does not easily drain unless I move it by hand. That is a huge hassle as I used to be able to just spray water and residue went down the drain.
I never treated the granite countertops and they have remained in amazingly great shape, other than some pitting in the work area the the left of the sink. Since that section of the counters has now been replaced, I will treat going forward. Soap & water on a sponge keeps them looking clean.
Same with bathroom marble counters. There is probably something I was supposed to have done to them, but I haven’t and they are fine. Perhaps dark colors are more forgiving.