I joined WhatsApp after many years of holding out, there was simply no other practical way to keep in touch with many people. The ways I mitigate the privacy concerns are:

1. I got an international eSIM, for the purpose of cheap roaming abroad but since I now had this extra phone number not tied to my identity, I used it for WhatsApp.
2. I installed WhatsApp using Island so it has access to just the contacts in the “work profile”, that is, just people who have WhatsApp anyway.