Yes, WhatsApp has finally been updated the to support the Default Apps feature. This means you can now make WhatsApp the default Calling and Messaging app on iPhone.

WhatsApp, like competing secure messaging apps including Apple’s iMessages and Signal, is end-to-end encrypted, meaning that no parties other than the ones in the chat, even including Meta, can ...

Until recent news involving the Signal app, it was a relatively unknown messaging app compared with WhatsApp to many nontechnical users.