A thought, with low epistemic confidence:
Some wealthy effective altruists argue that by accumulating more wealth, they can ultimately donate more in the long run. While this may initially seem like a value-neutral approach, they reinforce an unequal rather than altruistic distribution of power.
Widening wealth disparities and consolidating power in the hands of a few, further marginalises those who are already disadvantaged. As we know, more money is not inherently valuable. Instead, it is how much someone has relative to others that influences its exchange value, and therefore influence over scarce resources in a zero-sum manner with other market participants, including recipients of charity and their benefactors.