I’ve been a funding member of the Wikimedia Foundation for over a decade. I have looked at their finances several times before and during financing them.
As with a lot of similar non-profits, a considerable amount of donations does not go into “running the servers”. You have to judge this by yourself, but they don’t embezzle any money and there is a reasonable bottom line. Wikipedia continuously helps tons of people, and the people who run the operation enable that.
You can download a full dump of Wikipedia any day. Compared to other lying companies, they have been true on their promises for some time.
Of all the $1 I could spend in a year, the one I give to Wikipedia is probably the least wrong invested, and that $1 actually already makes a difference