I don't think it would really be any more difficult if it were binary. The only real reason to use XML is better integration with HTML, CSS and JavaScript, which is admittedly a compelling reason.

But I think he's right - it would be nice if there was a "proper" binary vector format that was widely supported.

I mean, I can write a line of Python that goes

  print(f"""<rect x="{x}" y="{y}" width="{w}" height="{h}"/>""")

I find this eminently easier than working with a binary format.

That's a pretty error prone way of writing SVGs though. In well written code you would use a strongly typed API and that API would be exactly the same for a binary format.

Think about how you write Protobuf files for example.

In the circumstances where I actually cared I would use a strongly typed language with nice wrappers, of course ;) The reason why I love SVGs is you can just belt them out from scripts and it's the easiest thing in the world. Same reason why I love GraphViz and Netpbm.