Good sticky rice is not well served by being eaten with a spoon. It sticks to the spoon too much which I find unappealing. Fork or chopsticks work much better.
Restaurants that serve dry rice usually have knife fork and spoon all available.
Yes, my family uses metal chopsticks too and all the other Koreans I know do so as well. My Chinese friends ask me how I can use such heavy chopsticks because I think they’re more accustomed to wooden ones. Anyways, to the OP, depending on the type of rice, it’s easier to eat it with a spoon than a fork. For rice that isn’t very sticky, it might be hard for people to keep it on their fork. For rice that is sticky, there’s less chance of it falling over the place if one uses a spoon. But, I generally use chopsticks because I’m more used to them.