I strongly agreed with this advice when I made less. Now I agree in principle, but in practice try to only discuss it with people on about my same tier. As per usual, disparities in money make for awkward relationships, with the weirdness increasing as the disparity increases.

It's so damned hard to identify the reasons for these disparities and what "fair" means, which is the best way to alleviate bad feelings. A couple years experience at the right companies, a particular project you've done, a team you've been on, the degree you have, the right people vouching for you, a lucky day of interviewing, etc. Tiny variations in those can take you from no offer to a crazy high offer. There's so much noise in the system that leads to salaries. In this imperfect information game of hiring, I can't fault companies for paying heed to those factors and paying more/less based on them, but after that information is revealed and you've been working together for a while, things usually don't equalize. The initial lucky/unlucky salaries persist.

The whole thing is weird. To too high a degree, the open salary discussion is now, "Yeah, I got pretty lucky." Doubly so with the stock comp we get in tech.