I recently had a house built, and most of the outlets do support grounding.

However, it's not very common to actually use them — many appliances don’t have grounded plugs, or the shapes don’t match.

I’d say only things like washing machines, microwaves, and rice cookers tend to use them.

are house fires and electrocutions common occurrences?

You'd think so, but the ground will either be at the bottom of the outlet, requiring a separate cable, or Type-B.

Nope, just live and neutral.

Nope, the ground is a separate wire that just dangles there and never gets connected. Over the last 25 years I don't think I've ever seen a utilised ground wire.

In North America, neutral is connected to ground. It's the larger pin on a polarized plug. Some devices don't use it; these usually don't have a conductive outer surface.