"well, if public transit documentation suddenly starts being terrible, will it lead to an immediate, noticeable drop in revenue? Doubt it."

First, I understand what you're saying and generally agree with it, in the sense that that is how the organization will "experience" it.

However, the answer to "will it lead to a noticeable drop in revenue" is actually yes. The problem is that it won't lead to a traceable drop in revenue. You may see the numbers go down. But the numbers don't come with labels why. You may go out and ask users why they are using your service less, but people are generally very terrible at explaining why they do anything, and few of them will be able to tell you "your documentation is just terrible and everything confuses me". They'll tell you a variety of cognitively available stories, like the place is dirty or crowded or loud or the vending machines are always broken, but they're terrible at identifying the real root causes.

This sort of thing is why not only is everything enshittifying, but even as the entire world enshittifies, everybody's metrics are going up up up. It takes leadership willing to go against the numbers a bit to say, yes, we will be better off in the long term if we provide quality documentation, yes, we will be better off in the long term if we use screws that don't rust after six months, yes, we will be better off in the long term if we don't take the cheapest bidder every single time for every single thing in our product but put a bit of extra money in the right place. Otherwise you just get enshittification-by-numbers until you eventually go under and get outcompeted and can't figure out why because all your numbers just kept going up.