There are a couple of ways to approach this information. One is to compare to the past. For example, comparing with 2008-2009 [1], they now spend 3.75 times as much on hosting, but 48 times as much on salaries, illustrating a more-than-tenfold relative growth in salaries compared to hosting. While hosting is not now nor ever was their only relevant expense, it is a good anchor point.
Another key difference over the last 15 years has been the introduction of awards and grants, which didn't exist then but now comprise $26.8M (15%) of their expenditures. This is where most of the ideological/controversial spending actually goes, rather than the salaries per se, but even more to the point, this one line item is more than 3 times their entire inflation-adjusted budget from 15 years ago ($5.6M times 150% CPI = $8.4M) and is still more than if we adjusted their entire budget using the hosting cost as an index ($5.6M times 3.75 = $21M).
[1]: https://upload.wikimedia.org/wikipedia/commons/a/a4/WMF_Annu...
Look, I'm not defending wikipedia, I'd just like to point out that comparing hosting to salaries is a quite strange metric. Hosting is cheap and relatively constant, adding features to the site or paying admins to maintain the quality of edits is scalable. How does throwing more money at hosting make a better product? It's not like the servers can't handle the requests.
Using hosting costs as an index is nonsensical. I wasn't able to find numbers for 2009, but since 2015 the monthly page views have remained almost exactly constant. So you might as well claim that they're vastly overpaying for hosting since inflation from 2008 is way less than 3.75x.
I picked hosting because it's a line item that exists across all of their budgets, it's a rough proxy for a web business's non-salary expenses, it's a big part of what you think you're donating to based upon Wikipedia's own language in their fundraising drives, and if nothing else, it's way more forgiving to the growth of their expenses than consumer price inflation is.
Ultimately every person has to decide for themselves whether they think WMF is a worthy recipient for their donations, but it is in no way operating on a shoestring budget nor staffed by volunteers anymore.