[OscarDC]

From my experience in France at least, nobody relies on SMS anymore and less and less people on regular calls, it all goes through Whatsapp.

Even I am guilty of that for both SMS and calls, having a single featureful app with contacts ordered by the most recent discussions descending (as in my country SMS is largely replaced by Whatsapp) leads to less friction than having to scroll through my actual phone's contact.