Consider this: you have a human, a gnome and an ogre all on a team. They make it to a hole in the wall.
If the hole is sized for a large creature, all can pass.
If the hole is sized for a medium creature, the human and gnome are fine, the ogre squeezes.
If the hole is sized for a small race, the gnome if fine, the human squeezes, and the ogre can't go.
If the hole is sized for a tiny creature, the gnome squeezes and the human and ogre can't go.
The thing is, the game is made for medium sized creatures by default. There are very few times you chase a pixie down a hole, but lots of times you do a goblin, kobold, or larger. Look at some of those dungeons from Yawning Portal; a large pc can't go into White Plume Mountain, the Hidden Shrine, or the Tomb of Horrors without near constant penalty to hit, AC, Dex saves and speed. That's no fun, especially if you are not going to give them the benefits of being large like reach out X2 weapon dice.
It's not elegant, but pseudo-large works better as a PC race. Unless you're running Against the Giants..