One of their differentiators is their performant web app which is something Apple is very much against. Then collaboration where Apple is also bad at on top of iterating fast, which Apple is also bad at for software.
There's just not much precedent for Apple caring about building out apps for 'pro' work - Final Cut and Logic Pro as historical anomalies.
I’ve used Sketch, Figma, Adobe XD, InVision and am generally unimpressed with these as prototyping tools. They overemphasize pixel perfect screen design & under solve the most important UX task: documenting the end-to-end workflow through a user task. My favorite prototyping tool was App Cooker, a workflow-focused app for iPad that sadly got acquired and discontinued. There’s a ton of room for innovation in the design space.