Ignorance of the situation on the first day of Gettysburg is one thing but not listening to his commanders (Longstreet in particular) on subsequent days was just plain stubborn arrogance. He had come to believe his own press and for a leader that can be fatal. A gifted general, yes but that is in comparison with the union political yahoos who were put up against him. When he encountered “that drunk” Grant as his adversary he found he was up against someone who had his own failings, did not worry so much about what others thought of his decisions and who did not believe Lee to be infallible. Lee’s really notable actions were in his efforts to bring about reconciliation after the war. He was a model of leadership in that respect.
Ewell could have taken Culp’s Hill the first day, had he told Early to just do it instead of waiting for Gen Johnson.
Longstreet wanted Lee to move around to the right of the Union army and make them attach the Army of the Northern Virginia. Unfortuately for that plan, the best place for that plan was at Union Mills, Md. General Meade had already selected Union Mills for the battle. Meade was ready at Union Mills, neither Meade or Lee were ready at Gettysburg.
Meade had an advantage in that Reynolds was the first senior general Meade sent to Gettysburg. After Reynolds was killed, the AOP had many problem. When Hancock arrived, things turned for the AOP.