As a guest, I've had hosts want to communicate via WhatsApp, and I always let them know that, with the exception of when I'm traveling to them, I prefer to keep all communications on the platform. I do this to protect myself, as I've had some sketchy hosts, just as hosts have had sketchy guests. My only concern with the platform is that I'm not always sent notifications of host communications, which makes me look unresponsive and therefore potentially sketchy. Sometimes messages from hosts have shown up on the platform for the first time a couple days after they sent them! I hate the phone and keep it turned off unless I have to use it, so I wish the platform were more reliable so that a host wouldn't have unnecessary cause for stress or suspicion.