BS. I visited city I grew up recently, met with a few (9+) people (25-32 years old) and only one of them had WA, most haven't heard about Signal, everyone simply uses SMS. It's simply multiplatform, works with their gradmas and no one wants to install __another__ app to send messages to people. No one cases about RCS that will be used to push QR codes and ads, people will use SMS for its simplicity and reliability. I'll be dropping Signal and moving to WA once Signal drops SMS support.