Of course I think removing plea bargains and changing nothing else would be an improvement (no hassle-free imprisonment and brutal torture perpetuated by the state? sounds great!).
If you're thinking something like "oh yeah, every charge should go to trial, and we should fund it better so there's not a ginormous backlog, and require a big burden of proof before you can detain someone awaiting trial" -- well, that doesn't count, as it's changing the court funding and bail policies too. As it stands now, making every charge go to trial means waiting ten years for a trial. Doesn't sound like an improvement to me.
Do you also accept the implications of the scenario I gave, in a post-A-G world? Where, rather than take the lighter punishment, you prefer that the defendant risk the heavier punishment or put himself at the mercy of the judge?
I think you're making my point for me -- to prevent the "plea bargains are bad" position from painting you into a corner, you attribute the inconsistency to the horribleness of the CJ system itself. That was my point all along! The problems you describe are problems with that selfsame horribleness:
A) Punishments are excessive.
B) Defendants get insufficient advice.
C) Trials (and waiting for them) take too long
D) You are detained (from excessive bail) while waiting for the trial
E) Prosecutors are likely to get convictions even in the absence of guilt.
F) The system is so capricious that people are willing accept a large punishment in lieu of riding it out for the true final judgment.
G) A-F lead to people people confessing in the hopes of leniency rather than because of literal culpability.
Hence my point -- those are the problem. If plea bargains were an independently bad thing -- let alone "the" obviously wrong thing that should be prohibited (on the level of non-competes etc), then it follows that we would be better off removing plea bargains even if everything else remained in its current state of horribleness.[1]
But that implication is emphatically not true! If you just banned plea bargains, A) punishments would be just as excessive, B) defendants just as flat-footed and likely to lose at trial, C/D) people would be in detained limbo even longer waiting for every last trial to play out, E) unwarranted guilty verdicts for the longer punishments just as likely, and F) a capricious/over-the-top punishment still waiting for them at the end.
And for the cherry on top, G) people would still be pleading guilty, still waiving their right to trial in the desperate hope that some judge might show mercy, and still being effectively rewarded for it!
And yet, I still wouldn't see the preference ordering under which that's better.
Would you say the same thing about plea bargains if A-G were removed? Criticisms would be far less defensible: imagine that the punishment for shoplifting is something relatively mild (one month plus record expungement) and a defendant were expecting 90% chance of conviction based on expert advice. The prosecutor offers a week in return for a plea, and the trial would happen in about a month and last a day. Do you really think it's an improvement to force the defendant into a trial or "whatever the judge gives them for a guilty plea"?
[1] Would you be able to say the same for the other horrors you mentioned? Non-competes, mandatory arb, etc? It seems that removing them and changing nothing else would be an improvement.