I agree with you (meaning G Gorden Worley III) that Wikipedia is reliable, and I too treat it as reliable. (It’s so well-known as a reliable source that even Google uses it!) I also agree that an army of bots and humans undo any defacing that may occur, and that Wikipedia having to depend on other sources helps keep it unbiased. I also agree with the OP that Wikipedia’s status as not-super-reliable among the Powers that Be does help somewhat.
So I think that the actual secret of Wikipedia’s success is a combination of the two: Mild illegibility prevents rampant defacement, citations do the rest. If Wikipedia was both viewed as Legibly Completely Accurate and also didn’t cite anything, then it would be defaced to hell and back and rendered meaningless; but even if everyone somehow decided one day that Wikipedia was ultra-accurate and also that they had a supreme moral imperative to edit it, I still think that Wikipedia would still turn out okay as a reliable source if it made the un-cited content very obvious, e.g. if each  tag was put in size 128 Comic Sans and accompanied by an earrape siren* and even if there was just a bot that put those tags after literally everything without a citation**. (If Wikipedia is illegible, of course it’s going to be fine.)
*I think trolls might work around this by citing completely unrelated things, but this problem sounds like it could be taken care of by humans or by relatively simple NLP.
**This contravenes current Wikipedia policy, but in the worst-case scenario of Ultra-Legible Wikipedia, I think it would quickly get repealed.
One bit of nuance my original comment leaves out is how flexible the citation policy is. Yes citations are required to include content on Wikipedia if it’s not considered common knowledge, but also it’s not that hard to produce something that Wikipedia can then cite, even if it must be referenced obliquely like “some people say X is true about Y”. This is generally how Wikipedia deals with controversial topics today: cite sources expressing views in order to acknowledge the existence of disagreements and also keep disputed facts quarantined in “controversy” sections.