WhatsApp is absurdly unsafe to use, but so are SMS/MMS and unpatched web browsers for various reasons. There is also no good way to segregate them, meaning that their compromise is a compromise of the entire device. Even GrapheneOS is now unsafe because it hasn't received patches for months. The only logical conclusion is that both Google and Meta are in on it. Something tells me that these vulnerabilities are why the government gives both companies a free pass.

Even if these doors were closed, there is also the cell tower communication chip that has significant access to the phone, and risks device compromise. All together, using a smartphone is more unsafe than using Adobe Flash back in the day, but nothing is done about it.