It sounds like you're talking about an aristocracy, and the quote even uses that word, so I wonder: do you think the aristocracy is responsible for most of the progress in the world?
I'd argue rather that, historically, progress has generally involved removing or disempowering the aristocracy.
In Huxley's day, that was more true[1] than it is today. Look at someone like Lord Kelvin, for instance. State-sponsored science wasn't really a thing yet; most of it was done by people who had the time and money to pursue it.
[1] That is, it was true of scientific progress. As you say, social progress often involved finding a way to destroy the aristocracy's stranglehold on money and power.
Baron Kelvin of Largs became that because of his work, not the other way round.
His father was a University Professor.
Having said that, in the history of science there's a surprising number of people who got to focus on their hobby due to family wealth, and access to all the best toys allowed them to claim a lot of firsts.
Weird, my view of history is that most progress in philosophy, arts, science, engineering, etc has come from aristocracy members who had the means to pursue something other than working for their next meal. That the aristocracy also spent their time exploiting the poor masses doesn't change that.
A casual check says the quoted text is from Huxley's Crome Yellow (https://www.gutenberg.org/files/1999/1999-h/1999-h.htm) and that the speaker is a character known only as Mr. Scogan, which some suggest is an analogue of Bertrand Russell.
I'd argue rather that, historically, progress has generally involved removing or disempowering the aristocracy.