Well, I'd say both yes and no. It can be regarded as a waste of time if people want to create professional-looking photos that they can be proud of as, unfortunately, smartphone photos usually have low picture quality compared to those made by professional cameras. But it isn't a waste of time if people need photos for sharing with friends on their social networks and in all kinds of messengers. Above that, smartphones make it easy for people to take photographs and capture memories irrespective of where people are and without special training thanks to phones' auto-focusing, auto-metering and easy-to-use cameras. To sum up, I wouldn't say that taking smartphone pictures is a waste of time, except those cases when people need professional-looking photos.