The problem is scale. Human-produced garbage content come in at rate X, but LLM produced garbage can come in orders of magnitude faster because you can spawn off agents to produce garbage content multiplying the output. The only thing limiting this is the economics and since the cost to produce this garbage can be so low, the amount that can be produced while still be economically feasible is massive.

It's the difference between a regular ocean wave and a tsunami. It's the difference between a person bumping into you and a being hitting by a speeding semi-truck. Scale is the problem with LLM garbage content.