I worked at Sorenson VRS with deaf people for six months while they were developing the mobile VRS app, as well as "BuzzCards", which was precisely a digital no

I worked at Sorenson VRS with deaf people for six months while they were developing the mobile VRS app, as well as "BuzzCards", which was precisely a digital notepad with many saved notes of things you'd say often, like Starbucks orders, addresses, basically just canned phrases or stuff to create on-the-go. While I was there, I never had to actually learn sign language to even communicate with my deaf coworkers, and this was in a technical environment. One coworker could mouth sounds adequately enough to understand. Most could read lips just fine. In some scenarios, we'd communicate with a small portable whiteboard. The deaf people I knew could write very quickly and tersely, which would be much more efficient than anything you could do via phone. This experience is only surreal if you've never spent any significant amount of time around deaf people.