Another vote for mostly just reheating frozen foods, frozen dinners, leftovers, and softening/melting things like butter, rock hard brown sugar, or helping honey or molasses to flow more easily. And of course there's nuked potatoes (as opposed to genuinely baked), and popcorn. I also use it to soften veggies for my birds on occasion. My Molluccan likes "cooked" carrots, and warm sweet potatoes.
I bought a micriwave searing plate many years ago that was supposed to heat up enough to brown meats, but not overheat of throw sparks that might damage the unit. It was some strange metal looking disc encased in a thick plastic larger disc.
I tried it a few times, but the meat (steaks and burgers) just sort of cooked to a greyish beige on the outside while being overcooked on the edges, and mostly raw in the center.
I think it became a frisbee for a while after that.