Having freelanced, contracted and worked at graphic design studios, ad agencies, font foundries, charities, finance companies, publishing companies and in government in the UK, I can safely say I've never seen any design departments use Windows as standard. None of these were in Silicon Valley and I've never worked in a coffee shop. This is also coming from someone who was almost religiously anti-Apple for many years.

You can certainly do good design on Windows, but there's no chance 90% of professional UI designers here are using Windows. And for user interface design Sketch is absolutelythe standard these days. I'd love to hear what similar tools were available in the 90s.