https://wikimediafoundation.org/annualreports/2022-2023-annual-report/
They have approximately $80 million in cash, and it costs them about $100 million to pay their staff. They have $274 million in total assets, counting endowment investments.
It's extremely unclear where that site came up with $400 million.
I'm not sure why you'd link to a two year old opinion piece on it, when all of their financials are publicly available and provided without commentary.
They received cash in excess of expenses of about $6 million, and including non-cash assets their total assets increased by about $16 million in 2024.
Their CEO makes about $500 thousand a year, and the rest of their executive team ranges in salary from $300 to $100 thousand.
It's not a small salary, but it's not preposterous for one of the most visited sites in the Internet that also operates as a charity to have decently compensated executives.
They are not in financial trouble, but it's not accurate to say they can keep the lights on for the next 50 years.
I donate a bit each year, and I wouldn't say they are bothersome. I get an email once a year where they ask if I'd like to donate again, not counting the receipt from the actual donation. It seems disingenuous to complain about the receipt.