I suppose that really depends on where you are in the world and how phones are used. Sending video works over WhatsApp here, and nobody uses anything telco or native for that (so no iMessage, MMS or RCS). Next one down would be FaceBook Messenger and then apps like LINE, Telegram and finally Signal. iMessage, MMS and RCS don't even make the list, including the entire 12 to 70 age range.