At least, bad if you let yourself be led by the nose by the platform's "recommendations."

If you're able to wrest control, you can have good experiences in sketchy apps. For example:

• Facebook with no Pages, just friends, sorted in chronological mode, and only subscribed to the particular friends that you actually want to know how they're doing.

• YouTube, but only for videos you find linked on some other place than YouTube; and then maybe subscribing to those videos' authors, and then directly checking your "latest updates" feed.

However, you can't really force kids to use these apps this way, and every step of these apps' workflows is trying to lead you out of this usage and back into their "idiomatic" recommendation-based one. So maybe better not to expose kids to the potential. (Or just give them an alternative interface without the drug-dealers-on-the-street-corners, e.g. YouTube videos discovered via an RSS reader, downloaded using youtube-dl, and loaded into Plex.)

This makes sense to me. Does somebody profit by me spending more time here? They are going to tune it to make me spend as much time as possible here.

Stack Overflow, hast thou forsaken me?

I wouldn’t characterize stack overflow as a delivery mechanism for ads in the same way that, say, YouTube is. Content creators on stack overflow aren’t there to make money by driving page views. (Rather, the mechanism driving page views is more utility than sensation)

That's a good point. You can't click "monetize" on your answers, but if you could you'd be right in that zone.

I don't know how useful an epicycle in your model this is. Content creators on Facebook aren't there to make money by driving page views either, and yet I assume you wouldn't say that Facebook is "good", by the standard were discussing.

At the same time, SO is hardly optimizing for return visits to SO in the same way that I would assume that Facebook is optimizing their platform for return visits and engagement to Facebook.

On the other hand, every time I go to SO to find a solution to problem ${X}, I find very interesting (to me) questions on the right, enticing me to waste time reading them. They are making an effort to keep people on the Stack Exchange sites.