> I forgot the source but the amount of prosecutions that are plea down is staggering.
I'd wager that 99% of the plea deals that occur in the world occur in the US. No other country uses it to the extent we do, and it's not even close. In many countries it's not an available option, or when it is and it's used, its use is heavily regulated and requires (meaningful) oversight by the judge on fairness, likelihood of conviction, etc.
And once you've accepted a plea deal it's not just a matter of making your plea - you also have to sign a whole raft of documents waiving a whole raft of rights, about appealing your conviction, about the right to present evidence in your defense in the future, or to witnesses, you have to sign a statement saying that even if you were to (attempt to) change your plea that it is your acknowledgment, "based on material facts" that the state is in possession of enough evidence to convict you.
See also: settlement in lieu of judgment in civil cases. There is an entire industry (debt collection) built around using the courts as a cudgel to coerce people into settlements for debts that they might not have a legal obligation to pay (because of the debt collectors' poor record-keeping, running afoul of procedural issues or consumer protection laws, etc.). Particularly for smaller amounts, attorneys will not represent consumers for defense, and (no matter what anyone tells you) judges defer to fellow lawyers if the issue goes to trial and a defendant is self-represented. Perversely, it's sometimes in a person's best interests to rack up larger debts, so that their case is worthwhile for an attorney to pick up, at which point they will likely try to negotiate a settlement rather than go to trial.
>No other country uses it to the extent we do
That is incorrect. Japan has a 99% criminal justice conviction rate because of so many plea deals.
https://en.wikipedia.org/wiki/Criminal_justice_system_of_Jap...