> Some of them are bound to if there is free market competition going on.

I trust the free market to solve over-litigation about as much as I trust it to prevent over-treatments in dentistry.

Free markets work well in many cases, but self-regulation that directly diminishes the total addressable market is not exactly common.

> they are certainly not going to let 6 million documents get in the way of a big settlement

No, but the loser will pay for their discovery – and after at most a few steps of indirection, by extension all of society.