As some pointed out, limiting #KOSA's enforcement to just the FTC doing it, wouldn't really fix the bill. Though, Blumenthal still wants AGs to be able to do so (despite them being even more prone to political grandstanding).
It's worth considering that, at best, it would likely lead to status quo, or worse, they'll be chasing every little possible moral panic (and historically, there have been quite a few involving minors), and it is very likely to be leveraged to disproportionate ends (which are in themselves harmful to many users on these platforms). There is also a possibility that it might be leveraged to political ends, and if you're a Democrat, that could take the form of another Republican president in the future.