> how accessible were VB apps to people who had sight-related disabilities?

Coincidentally, they were very accessible because they used corresponding Win32 components for all logical UI entities, despite being fixed in layout. Therefore, they worked really well with screen readers.

Sadly, this is not the case with UI frameworks, which render the screen as a Vulcan/DirectX/OpenGL canvas. By the way, for today's Electron-based apps, you can use WAI-ARIA (or similar) standards to achieve a similar level of accessibility.