Wikipedia had a really good year in 20-21, their most recent financial report.
They took in $162 million, against an $111 million operating budget, and came out of the year with $240 million in assets.[1]
So they had about half a year's surplus, and wound up with ~2 years worth of savings. And yes, that's a simplification, a good chunk of those assets are necessary to continue operating and cannot be liquefied to cover operating expenses.
In 19-20, they took in $120 million against a $111 million operating budget.[2]
[1] https://upload.wikimedia.org/wikipedia/foundation/1/1e/Wikim...
[2]https://wikimediafoundation.org/about/annualreport/2020-annu...
So, yes, Wikipedia is doing well - as we should hope they would be. But no, they are not rolling in it, and yes they do depend on our continued support to continue doing well.
Edit: The article linked in the tweet asks valid questions and puts the stats in better context, but the twitter thread presents the numbers in a way that is very, frustratingly, misleading.
Note that "Direct support to websites" includes things like designing and implementing more intuitive article editing UI, which while potentially worth it isn't the kind of "obviously we must do this" that keeping the site serving is.
For example, in 2016 Wikipedia served a similar amount of page views as it does today [1] on an operating budget of about half [2]. Go farther back and my impression is it's much more dramatic, though I'm not finding good page view statistics for, say, 2010.
[1] https://stats.wikimedia.org/#/all-projects/reading/total-pag...
[2] https://foundation.wikimedia.org/wiki/File:Wikimedia_Foundat... vs https://foundation.wikimedia.org/wiki/File:Wikimedia_Foundat...