I was forced to stop using WhatsApp a while back because they simply stopped supporting my phone, and I sure as hell wasn’t going to buy a new one just to use WhatsApp. I came to the conclusion that anyone that doesn’t bother reaching out e.g. via SMS isn’t a real friend anyway, and indeed it hasn’t affected me personally much. There are some people I’ve lost contact with completely now, but we didn’t have proper conversations when I still had WhatsApp anyway, so not much was lost.