What, specifically, do you think is chartjunk? There are things that might be optional in some cases, but the article specifically names them as such and has a whole section on ways to combine different elements in different ways?

Quite. To be honest, I hoped the original URL would be more like this one -- https://physics.nist.gov/cuu/Units/checklist.html -- which is much more of a "metric system standards" page...

Aside from the branding section, which author handles realistically...I don’t see anything I would consider chart junk.