> Run a study and then talk.

It has been running for centuries. It’s called typography. Its rules are not arbitrary and legibility is the most important one.

No need for scare quotes around readability. It’s a science.

There’s a latitude of contrast ratio between which human eyes can comfortably withstand and discern tones. It varies across individuals, of course, but not as much as you might think. No human sees ultraviolet, for example. And even if you have 20/20 eyesight, you need to design for a much wider spectrum of the Bell curve if you care at all about accessibility.

You might be interested in checking the history and methods behind CIE 1931. Also, “The Elements of Typographic Style” is a deep but fascinating book.