Transition lenses are the ones where you have reading lenses in the bottom and long distance lenses at the top? I guess they are for anyone who suffers both from myopia and hyperopia. Although you could just get contacts and a pair of reading glasses.

Not really, but you see them a bit more often with old people, because the lenses inside the eyes become less flexible with age.

However, an alternative can be contacts with reading glasses. Can be frustrating to pop out the glasses often. Probably not good for driving idk