Same with combustion vehicles and the climate: block cars in cities a couple of days per week, individually selected per person.
These sorts of suggestions always remind me of the various people who, during my teen years, loved to give unsolicited advice suggesting that if my parents didn't apply arbitrary restrictions to my hobbies, they'd be setting me up for failure (my hobby was teaching myself higher level math, gpu programming etc, things that led to my current career).
Day restrictions for vehicles can be temporarily worthwhile when the air quality becomes too poor or as a transitory step towards a more significant ban and restructuring of thr city's transportation systems. But if kept in-place as-is long term, they just lead to people finding workarounds (like second cars).
I don't think it's a punishment so much as a public health measure. Like restricting who can buy tobacco and alcohol and where they can be consumed, or car pollution regulations.
Where I'm coming from is, I think social media is one of, if not the top most, destructive forces in society today. It provides a huge megaphone for people who benefit from spreading misinformation and actively encourages conspiratorial thinking. The attention- and ad-based business model rewards the worst kind of communication, and we can see how quickly it has been abused to destroy our society. Being one of the worst inventions in human history is not a "low bar."
I don't know what the fix is, but I know that the current situation is very much not working. I'd like it if we tried some kind of regulation to reign in this poison we are all collectively consuming. Again, something similar to how we regulate other harmful substances like alcohol and tobacco. We don't need to outright ban it, but we need to do something.
I'd rather see targeted actions, say, bans or severe restrictions on recommendation systems/algorithmic feeds. Limit how far they're allowed to reach from your personal network of follows, limit the percentage of posts that can be algorithmicly driven, controls on the balance of popular posts vs relevant posts, ban infinite scrolling feeds, limit how strongly sites may neuter their search systems, maybe require warnings after certain levels of continuous usage.
If the goal is to directly and forcibly limit usage, a "credit" system would be preferable, you have some weekly time allocation for large-scale social media usage (forums were technically social media, but were far healthier than platforms like reddit, facebook, X), and you can use that allocation however you want. Your allocation can grow kr shrink based on your specific circumstances (career, history of healthy use of social media, social circumstances like living far from family, medical circumstances).