To others it was the most frustrating aspect of the whole series. It was like a four and a half season rule that went on for the entire series. It didn't help that the flying was taken up by other characters like Kara Zor EL.
Could've had it been like Jessica Jones can't fly very well.
Even in the Lois & Clark pilot he had the ability to fly long before he had the suit what was wrong with that?
The writers did admit they couldn't afford to have him fly week to week or once in a while.