So they’re wrong because it’s been two decades? But also Apple did the glass look before Microsoft even. https://macosx.com/threads/when-did-apple-do-away-with-window-transparency.266992/

And like others have noted.

It’s worth noting that FVWM on Linux had transparent UIs in the 90s and Compiz had a full Aero like desktop a year before Vista was announced. So no, neither Microsoft nor Apple are the innovators here.