The addiction economy is hard to deal with for anyone - regardless of age. So, I agree this is definitely not a solved problem, but from what I see the only viable way forward is actually to do pretty drastic things like not own a smartphone.
You can remove most objectionable elements with uBlock filters. Also dedicated browser extensions exist to deal with the biggest offenders.
If you're willing to use alternatives and do without the services entirely then simply DNS blocking a handful of big names on your LAN immediately resolves the majority of the issue.
