On overall I agree that having a larger audience is better for WP.

But most WP users are quite passive, and unfortunately a very few are extraordinarily active, so the quality of the WP they patrol, depends heavily of their biases. As they are few, there is no natural moderation.

But having a quality article is not enough, it is also important to have quality articles on a reasonable range of topics, and this is not true for some WP (French WP for example)

Same article since 2012 about cancer vaccines, only 42 words! https://fr.wikipedia.org/wiki/Vaccin_contre_le_cancer