>It's as if YouTube forgets about your previously viewed videos and channels, and tunnel-visions you into watching content around your most recently viewed single video.

Which, if your primary concern is maximizing engagement, makes perverse sense. Viewers are more likely to be attracted to content similar to what they just watched than content they watched less recently.

Edit: I just realized the opposite might be true as well... some viewers might be attracted to videos which appear to contradict their preferences as well, just to be able to criticize or debunk it in comments. There's probably a relationship between this and successful clickbait thumbnails with their random arrows and circles that don't actually indicate anything.

>primary concern is maximizing engagement, makes perverse sense.

I agree. But considering online platforms have, more or less, become de facto town squares, it's no longer responsible for a tech company to ruthlessly optimize for user engagement at the cost of stability of democracy.

There appears a conflict of interest for those platforms because they don't intend to act as de facto town squares... they are businesses, and arguably don't have an obligation to anything but profit, regardless of their popularity or ubiquity.

Despite this, their nature as "town squares" affects the market whether they want it to or not. If enough viewers disengage because of their their ruthless tactics, or change their behavior in ways that don't fit their algorithm, that creates a business case for more ethical behavior... which would probably be more compelling to them than an argument for preserving the social fabric or democracy.