Why is it so hard to free wrongfully convicted people from prison?

[getagrip_already]

2. once convicted, it usually takes a pardon or commutation to get released....

Because you have been convicted, the rules of the convicted still apply to you, and scotus has made it nearly impossible to appeal and get new trials.

Then you are stuck on the treadmill of parole, and since you haven't admitted your guilt, they usually won't let you go early.

And because most of these people have absolutely no means to pay lawyers, and are typically from the most villanzed populations.

Governors hate to pardon/commute, because it can come back to bite them during election cycles.

The system is there to grind people down, not treat them fairly.