First, from my dishwasher, bartender days -- a double sink makes washing dishes easier and uses less water; and, provides some options when (my wife) cooks pasta, shrimp, etc.

Secondly, when underway if you want to avoid dishes, glasses, coffee containers, etc. -- the smaller sinks give you options that are less likely to break containers or spew liquids.

Thirdly, if provides some options for draining pasta, shrimp, etc. while leaving the other sink available.