> I needed to make diagram,s so I compared a few options and quickly settled on "draw.io"

So this not rules out that he didn't at some point. But still to my graphic designer eyes choosing either Inkscape (and even more, Figma) for doing simple diagrams is really, really weird.

* Disclaimer: I'm a heavy Inkscape user, it's been one of my main tools for all of uni and my professional work since 2006 - yes, it has some unpolished details here and there, but still it's great and (for me) miles better than any paid non-free tool