For sure, in some ways perhaps reverting to a low trust environment might improve quality in that it now forces harsher/more in depth reviews.

That however doesn't make the requirement less exhausting for people previously relying heavily on those markers to speed things up.

Will be very interesting to see how the industry standardizes around this. Right now it's a bit of the wild west. Maybe people in ten years will look back at this post and think "what do you mean you judged people based on the code itself that's ridiculous"

You said "hence the point its author is trying to make must be true" and "hence it must be modeling the world with high fidelity".

But it's more like "hence the author is likely competent and likely put in a reasonable effort."

When those assumptions hold, putting in a very deep review is less likely to pay off. Maybe you are right that people have been too complacent to begin with, I don't know, but I don't think you've framed it fairly.

The heuristic is "this submission doesn't even follow the basic laws of grammar, therefore I can safely assume incompetence and ignore it entirely."

You still have to do verification for what passes the heuristic, but it keeps 90% of the crap away.