More information is generated in the material world per second than is generated on social media per year, but we haven't seen that as a reason to dismantle the justice system.
Nobody was advocating for dismantling the justice system.
Social media specifically lends itself to widespread and high frequency libel, fraud, threats, and other illegal acts. What "material world" information manages to do so at a similar rate?
The vast majority of social media 'libel, fraud, threats, and other illegal acts' involves an unverified identity as either the sender and/or receiver. It can all be ignored with a click of the button, or often even easier because one never sees it in the first place.
And why does it matter if the total number of messages exceeds our ability to read them? People don't sue over an aggregate of messages but for individual messages. If there are too many people suing then the courts will simply take longer and longer until an equilibrium point is reached.