FWIW I implemented SARIF output in GCC 13, which gives a machine-readable interchange format for the errors. It's viewable by e.g. VS Code (via a plugin). Hopefully that makes it easier to grok the messages.

You can see an example of the output here: https://godbolt.org/z/aan6Kfxds (that's the first example from the article, with -fdiagnostics-format=sarif-stderr added to the command-line options)

That doesn't cover the diagrams though (which I currently serialize in SARIF form by making a placeholder Markdown text containing "code" containing the diagram).

I experimented with SVG output for the diagrams, but didn't get this in good enough shape for GCC 14.

I've got a few ideas for more general UX improvements with how we do diagnostics, which I'll try in GCC 15 once we're finished focusing on GCC 14 bugfixing.