Mobile devices are the key to engagement for everyone today. Whether we like it or not! So if we want to connect with others in our family or friends, or others, being able to use a phone becomes necessary.
These days however, a phone is more than just a device for making and answering calls. For children up to young adults (and older?) it is also used for entertainment where owners can access YouTube, play movies and listen to music. Additionally, the means by which these young people communicate with each other is via messaging, using one of a myriad of the messaging/chat programs. Using the same programs, photos can also be shared other users.
Calls are not necessarily purely audio calls; people can also make video calls so that each person involved in the call can see each other.
To belong to or be part of this new world, it becomes necessary to able to do more than just make/answer a call. Why? If you (as an older person) want to chat with your son/daughter or grandchild, being able to chat using messaging functions is helpful, if not a necessity.
Even when you sent that first message to other person, it is also helpful to introduce yourself to the other person you are sending the message to so they know who the sender is, to cater for the scenario where you are not in the other persons contact list.