It's absolutely an argument that filters are unnecessary. It's not a good one. It combines survivor bias with the false implication that today's internet is the same one we had in the 90s; it is not.
I'm opposed to KOSA - I think vague appeals to "preventing harm" are going to be weaponized against queer kids in red states and cause real harm... but again, I think there are far better arguments against it than the "we came out fine" one anti-vaxers and corporal punishment advocates trot out.