> 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.