Since the post Civil War writers attributed an almost godlike knowledge to general Lee, he was over rated by them. Although a skilled commander, he was not all knowing and was not always successful when taking reasonable risks.
He was highly skilled and over rated at the same time.
The primary reason that General Lee was over rated was to distract from the facts. The Confederates never seriously challenged the US naval supremacy. The US took control of the thinly settled far west in 1861-1862.
The armies in the Mississippi theater broke the continuity of the Confederacy in 27 months, starting from non existence and gaining complete dominance.
The US had existing tax and finance systems. It was able to finance an expensive formula despite errors.
There is not much evidence that the Confederacy every constructed a tax or finance system. In that regard it was either an insurgency, or a retreat in a fuedal system of levies and impressment. General Lee cannot be blamed for that.
His responsibility lies in not admitting that the strategy he had been pursuing had clearly failed on November 11, 1864. It was time to admit defeat.