You 100% do not need to use WhatsApp. The only way you will ever leave WhatsApp is by doing so uncomfortably. I decided to not only delete the app, but totally nuke my account in settings before deleting it across every device.
People will SMS you, people will come to [insert fav privacy messenger] with you. I know multiple, unrelated people who have had this experience.
Privacy is limiting third parties access your personal life, if you're limits aren't "too tight" then they're "too loose"
I'm currently mustering up to tackle a bunch of other loose ends like these. You'll thank yourself for doing it.