I'm carded for R-rated movies. And I get talked down to a lot. When I try to go rent a car or buy an airplane ticket or other stuff adults do I get 'Okaaaaaay honey.' I remember when I was 18 getting crayons in a restaurant.
It really depends but generally speaking just because of the mechanics of it voice-over is easier because there is no hair no makeup no wardrobe no fittings no line memorizing. You don't have to me woken up in Russia at 6 in the morning and go film a scene. It's just easier on the body the family life to do voice-overs.