It is relevant. I didn't have any means to test it, and that's what I saw as sufficient back then. You never admit you were wrong, I assume?

edit: you edited your comment, so here is the lighthouse.org page: https://web.archive.org/web/20080211110529/http://www.lighth... There was no ratio, so it's just my gut feeling which WCAG 2 had apparently decided was not enough and I didn't know it back then - not that there were enough tooling.