Meade had only been put in command of the Army of the Potomac a few days before Gettysburg. He actually did awfully well considering he had just been thrown into the command. He didn’t do anything brilliant in maneuver but he picked the right defensive positions and let Lee break his army attacking a stout defense.
Meade can perhaps be faulted for not following and counter-attacking Lee’s army aggressively as it retreated south. There may well have been an opportunity to change the war even more decisively than occurred at Gettysburg itself (which was “the high water mark of the Confederacy” according to many historians).
But Meade had so little time in command, and many uncertainties about what was going on in the aftermath, so he may have been wise to take a cautious view of the post-Gettysburg situation. Arguably, Meade might have dealt a catastrophic blow to Lee’s retreating army, but it may have been hard to know that at the time.
Actually Mead didn’t pick the ground at Gettysburg, it was Gen Buford who got the high ground.