If the active elements were convex instead of concave, I can imagine this being useful for people with visual impairments. How does this compare to existing technologies for braille displays?

https://en.wikipedia.org/wiki/Refreshable_braille_display

The technology hasn't changed at all since the 1992 film Sneakers with the blind character Whistler. https://youtu.be/GS3npSv8iuM?t=124