It's not so easy to prove harm from internet access.

There are studies that suggest social media can harm adolescent mental health[1] but there are also studies that suggest the magnitude is small enough that we don't really know.[2]

It needs more study (and it sounds like what we really need is more transparency from big tech so that it can be better studied).

For an actual argument against KOSA I would say it doesn't at first glance look like it will target issues that are likely more important: peer pressure, bullying, suicide promotion/romanticization, etc on social media.

Edit: Having spent more time reading the KOSA bill (thankfully linked by another commenter) it does actually appear to try to target the biggest known issues to help minors. Some of the bill seems reasonable.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10476631/

[2] https://journals.sagepub.com/doi/10.1177/21677026231207791#:...