Remembering Windows 3.1 themes and user empowerment
Unpopular opinion: optimising for "branding" is what killed theming. Everyone wants to have their own custom colour theme, brand-associated font or button style, which clashes with uniformity of system controls.If everyone renders buttons in a custom way, they bypass the native, theming-capable, accessible-by-default system controls. As long as product managers are happy, it doesn't matter that users aren't.