You can use Google Duo to make voice or video calls for (other than data costs) free, Google hangouts also has voice-only plus video options and of course Google voice integrates with the classic telephone network and has cheap international rates.

Google Fi has free calling from the US to over 50 countries and otherwise their plans start at one cents a minute depending on destination. https://fi.google.com/about/unlimited-calling/

Most of my friends from Asia tell me WhatsApp was and is popular because it carried voice over data, bypassing the PSTN which apparently has very high per-minute rates.

If you want to go slightly higher tech there are telepresence appliances like 8x8, Amazon or Google IOT devices or you can just use sip phones and call between the devices free of charge using your own pbx software or a free service like Callcentric's IP Freedom plan.

There a million options that either let you opt out of Facebook's data collection and trade it for Google's, or just opt out entirely.

I call my family for 1 cent per minute.