It also relies on things like eyewitness testimony which has proven quite unreliable. All in all it is a very dated system that is in serious need of an upgrade.
On the whole, the American system -- with its ancient safeguards inherited from the English common law -- does an excellent job at deterring and ferreting out serious crime while protecting the innocent. The American criminal law assumes our innocence; tells us the accusations against us; can only search our bodies, homes, and things with good reason, as decided by an impartial judge; compels our accusers to face us in open court; prevents juries from hearing unfairly inflammatory evidence; and generally allows most of us to live our private lives unmolested.
That's a good foundation.
On the other hand, the American criminal law also imprisons more human beings than any other law on the planet by an absurd margin, turns poor black areas into humiliated angry police states, turns marginal offenders into hardened criminals with sociopathic prisons, accepts prison rape as a mere cost of doing business, drives people insane with solitary confinement, and, as you point out, unfairly convicts people on unreliable evidence.
But we can deal with these problems piecemeal while preserving the good.
Are we sure we are talking about the same justice system?
Look up Dario Gabbai and what he says the color of cyanide-poisoned bodies was (blue), then look up the real color cyanide-poisoned bodies turn into (red).