Why do those who say they don't want to intrude think that their children won't mind intruding on their days?
I hear this from my own mum - that she doesn't want to phone any of her children/grandchildren as she doesn't want to intrude, but I don't buy it. She is as likely to be busy as any of us, and as we've all said a hundred times, most people just don't pick up if they are busy, but they can see a missed call and will reply when they can. I'm afraid it's not reasonable to expect everyone else to make the effort and not take some responsibility yourself.
To go back to the original question, my children tend to WhatsApp rather than call, and my daughter more than my son - she sends photos and videos as well as messages. That's fine - we are all busy people. Interestingly, I don't expect an instant reply when I send a message, but if I don't get back to my daughter immediately she gets very impatient?