> I feel like that is the kind of response that is an example that could be used for "sealioning" on Wikipedia.

Not at all. Mainly because this is asking for the first line of examples, not repeatedly bogging down the conversation with constant requests for additional evidence.

Also it matters because in this kind of vague remarks that Wikipedia is unreliable, or that articles are wrong, almost always the people claiming this fail to provide specific examples, instead relying on some general feeling of frustration and shared belief that it must be true. But if they provided a specific example of a factually incorrect article, maybe other people would disagree. Or if they provided an example of ideological bias, maybe it would turn out the complainer is in the minority in believing that was biased. And if it turned out that this were controversial topics that most encyclopedic articles struggle with in some form, maybe it isn't a problem with Wikipedia. So examples matter!

See my other response for why engagement is usually pointless in cases like this.