One of the missed opportunities of 5e is that once you take ability score modifiers out of the equation, there is little actual "power" in racial features. There's a bit of flavor, but it's not an equal pillar of character creation. And this lack of design space means that giving a race a significant bonus like large/tiny size, permanent flight, and the like doesn't have enough of an balance in opportunity cost of missing out on the features another race would give.
If all of the races meant more, then you could have a centaur PC who's the same size as the MM's centaurs and that's okay - that large size is nicely balanced by not getting all of the goodies some other class gets.
All of that said, I remember playing a half-ogre out of Dragon mag back in AD&D and it would be great to revisit that in 5e if Call of the Netherdeep does it in a 5e-reasonable way.