Wikipedia is extremely broad. According to the article, the SEP has 1500 entries. Each of those is no doubt better than an individual Wikipedia article (more cohesive, more in-depth, etc), but I bet there's two orders of magnitude more Wiki articles on philosophy (nevermind other topics!). It no doubt has much wider coverage. How's that for "more comprehensive"?
I guess I'm just complaining about stretching a word to mean something more specific than it usually means. I think of comprehensive as including both in-depth focus and wide-ranging reach. So when the article counts only one of those aspects, and omits the other from the checklist, it feels like cherry-picking the outcome.