Well, then it wouldn't be
easily demonstrably false, but it would still be crying out for some actual evidence which doesn't seem obviously forthcoming.
"Actions speak louder than words". "History shows us". Well, what actions and what history show that "effective altruism" exists for people who want to hoard obscene wealth and feel virtuous about it?
The founder of the movement, in so far as that's an identifiable single person, is William MacAskill. He (allegedly, but I've not heard any claims that it's a lie) donates everything he earns above the UK's median income, which is something like £26k/year.
(MacAskill surely deserves some criticism for helping to set SBF on the path he took -- so far as I know he didn't at any stage suggest or endorse lying, cheating, and stealing, but he did suggest something along the lines of "earn as much as you can and give as much as you can" and we know how that ended up. But I think we should distinguish "gave one person advice that ended incredibly badly" from "primarily wants to help rich people feel good about hoarding obscene wealth".)
Another candidate for "founder of effective altruism" is Peter Singer. He works as a philosophy professor, which I can't imagine is an especially well paid job, and I know he gives away a substantial fraction of his income. (He got a $1M prize not so long away and gave away all of it.)
Another is Toby Ord. Like MacAskill, he's set a not-very-high threshold and gives away any income he gets beyond it.
It doesn't seem credible to me that these people's intention was to help people justify hoarding obscene amounts of wealth.
So maybe the claim isn't that that was the original purpose of the movement, but is that that's what today's typical "effective altruists" want. I'm not sure how best to evaluate that. We could take a look at effectivealtruism.org and see what advice it gives -- does it say "you should get into a highly lucrative career and give a bit of money away" or something of the kind? Well, no. They say e.g. "A common misconception is that effective altruism is only about donating money to global health charities or ‘earning to give’. But community members support many causes besides global health, only a minority are prioritizing earning to give, and effective altruism is as much about how to use your time effectively as your money. In fact, the organization 80,000 Hours argues that for many people, their career decisions matter more than their decisions about where to donate."
There's an annual-ish "EA survey" (insert here all the usual caveats about surveys giving you unreliable and biased information) which suggests that between ~15% and ~25% of self-identified "effective altruists" think of themselves as "earning to give", which is what I would expect anyone to say who was in it to hoard obscene amounts of wealth and feel good about it.
Maybe I'm looking in the wrong places. What's your evidence (or callalex's) that EA exists for people who hoard obscene wealth or want to?