Good points. Except I would contend the problem arose not from the conclusion of “Equality” as an ideal, but rather its over-extension.
Equality, as in “All men are created equal” is at the very root of the American Revolution. But that men are created equal does not imply they will all achieve and be rewarded equally. All people should be equal in the political and legal areas of life, we all have the same rights.
Where Equality went off the tracks was when it started demanding Equal results. Everybody had to have the same Stuff, not just the same Rights.
All the leftist crap of the last 200 years has followed from this basic misunderstanding of what Equality means.