Wikipedia is crowdsourced but not the whole project is being contributed or managed by everyday normal you and me sort of people. Wikipedia actually relies on an army of bots to keep the quality of its articles high and trolls at bay.
The BBC has a great look at the bots that work in the background. An example, the ClueBot NG, is used to detect vandalism on Wikipeida. The program was administered by five volunteers that uses algorithms to detect when an illegitimate edit has been made to an article. Developers of the ClueBot NG say they catch a total of 55% of all vandalism.
Could Wikipedia rely on bots entirely in the future? With human editors and admins declining, would the encyclopedia turn to machines to write articles? At this point in time, as the BBC points out, they're not allowed to do so.