The review shows a pretty limited understanding of Mexican history, as the Dr. fails to mention the biggest elephants in the room—the politics of religious authority especially in the countryside, the related rabid anticommunism, and the broader context of power in Díaz Ordaz's Mexico and in the post-Revolution era even more broadly. I can only assume that with the single mention "local demagogues" Dr. Svet had in mind the priest, but he really dances around the major problems the film taps into in its portrayal of these events, and he instead focuses on the easier targets of criminals and corrupt businessmen.
The film isn't essentially about a "dangerous vacuum" in a remote hinterland where "shady businessmen, and powerful drug lords" hold sway, since looking at the events in Canoa in even just a slightly broader context leads us to confront the arguably even more shameful memory of the federal government massacring student protesters in the D.F. only weeks after the Canoa massacre as part of a concerted effort to destroy the student movement and suppress the Left, followed by an erasure of these events from the country's official memory. These are forces that are so insidious and interwoven that it's hard to summarize them, and certainly the problem is not one of drug cartels running Mexico and the federal government failing to maintain order, as Svet outlines it. The state and civic-religious authority, the climate of fear and rabid anticommunism and widespread disenfranchisement were much more at the roots of these events rather than the state failing to maintain order and leaving power available to "bad dudes," as Trump would put it.
At the end of the film, there's a sense of "business as usual" going on, but again the political reality that continued on in the years following 1968 was not all about the spread of drug trafficking; if it's any one thing it's clearly the continuation of "dirty war" carried out the federal government and the military, with U.S. backing, leading to another massacre of students in 1971 among many other atrocities. I guess I can only wonder about Svet's reasons for ignoring all that, as he explains what Mexicans should do in light of the film.
Also, in Mexico the film is generally considered a major classic of their national cinema and was already widely seen on DVD, so it's not as if Mexicans need to "discover" the film 40 years after its original release just because there's now a Criterion edition of it. But the review argues that "young Mexicans" should be urged to go see it again in theaters, see their country in a different way, and then "actually do something" to make Mexico better?

I'm not sure that's how national social and political upheavals tend to operate.
And as a footnote, because Svet was clearly very moved by the way the film portrayed these events and notes that it's "much like an objective documentary," I don't understand why he claims that "the story ... seems grotesquely amateurish." Oh well, yet another review to remind me that I obviously should've just looked at the screenshots alone.