Depending on the technology and individual, there is very little 'healthy' technology for teens. I don't say 0, far from it, but given whats usually available its really a minimal set.
Also there is very little of 'technological skill' to learn, clicking around could be understood by little kids, rest is just usage. Sure, hackers and generally brilliant folks may actually thrive, but they are rare and far apart in general population.
There is endless stream of highly addictive technology, and those kids have absolutely 0 defenses against it. Alcoholics also never notice when they crossed the threshold of a proper addiction, its quiet and sneaky business as usual till you hit the wall hard in some way.
What a great way to prepare for adult life, entering it with some heavy but peer-accepted psychological addiction or two. What could go wrong, raising a strong balanced individual right. Pride for any parent.
Sadly, you are right. Everything is made to retain attention, feeding into the addiction. Games do this with live services and 'daily events', social media apps are tailored to keep you constantly hooked (I'm reading 'Algospeak' at the moment which talks about how linguistics plays a role here, recommended read).
I don't think I know of a good parenting solution to this, to be honest. But if parents read this and want to chime in, I'm quite curious to see how others handle this. And I'm assuming the HN parenting crowd is a technical audience that understands the risks involved.
I have a toddler. We never let them play with a smartphone or tablet. Occasionally we show family photos, and rarely we will show them a video. But an adult is always holding the device and in control.
The toddler does have a "Yoto," which is a thing that plays music and little stories for kids. They love it, and I think it's kind of cool. We also let them watch a few shows on TV, but only during the afternoon. It usually gives the adults a chance to do something else, like cook dinner, but if there's an adult available, we try to do something else besides watch TV. Jellyfin has been great for curating a small list of parent-approved shows, with no other shows vying for my kid's attention.
When they get a little older, I would like to introduce video games. It would be either a home console with no online connection, or maybe some kind of Linux box that I've locked down.
We will be avoiding social media and similar platforms for as long as we can. That is where I feel the most worst, brain-warping dangers exist.