I'm a designer at Twitter and our design team has been using Sketch for UI design for the last few years. I believe the same situation occurs at FB and many other design teams unless doing very particular photo work or iconography/illustration.

I don't disagree with that. I also work at Twitter and use Sketch.

I'm just saying that Sketch is not a substitute for Photoshop. It never was, nor should be. You completely misunderstood me.

Sketch is already used in 60% of all the tech industry, while Photoshop and others sit in the 40%. Sorry.

The designer producing work for my team is using Sketch and it looks really good to me.