At level 14, flight is near the bottom of the list of things that make my DM life hard so it doesn't surprise me at all that it didn't cause any problems at your table.my first character that got to 20 was a human grave cleric. it was a 3 year campaign and the dm gave me flight at about lvl 14. it was a story beat that resulted in me being able pop fiery wings with 90' fly speed for 10 minutes per day.
it created exactly zero problems at my table.
i'm not saying it WONT create problems, just that the problems you guys are describing seem to be issues with the table, not the game. ie: stop playing with players who get off on trying to ruin the dm's life