Totally agree. Equity is not something we should value for its own sake.

I will, however, suggest that, within certain contexts, it might be true that equity could serve as a useful heuristic for something with real value. For example, the disparity of wealth between Bill Gates and, most other people means that Bill gates has more ability to sway society and politics. It's essentially as if he has more votes than everyone else - which you could argue is un-democratic. And I think you could hypothesize that an un-democratic situation like that might have a danger, in the long run, of de-prioritizing most people's well-being, which might ultimately result in most people actually being less well-off, relative to their previous lifestyles.

But that said, I think, for any given scenario, the burden of proof lies in showing that equity is a relevant heuristic for predicting well-being, rather than assuming it is. And so, in general, it's better to start off by assuming that equity isn't relevant.