Here is their FY 24–25 Audit Report. To wit, their net assets were $296.6 million, while their total internet hosting expenses were $3.5 million. So the claim that hosting expenses make up a trivial fraction of their total assets would appear to hold true even moreso today than a decade ago.

Granted, the FAQs for the report state that "The vast majority of […] revenue came from donations […], as well as investment income, Wikimedia Enterprise revenue, and other revenue primarily related to a cost sharing agreement with the Wikimedia Endowment".

I remain suspicious of the large increases in "Salaries and wages" year-over-year compared to other expense categories.

Operating expenses don't necessarily equate to total expenditure. The article also mentions that fifteen executives took home a six-figure salary in 2015; that doesn't strike me as particularly efficient.

Notwithstanding, what I originally said was not prescriptive. People are free to spend their money as they see fit. Even I have donated to the Wikimedia Foundation in the past and still believe that they provide invaluable resources for the common good.

Where I take issue is the fact that the messaging in their campaigns often gives the impression that the organization is scraping by on user donations, whereas in reality they're sitting on a pile of assets that would ostensibly be in the 99.9ᵗʰ percentile of household net worth in the US.