[dbaupp]

Floats (and shorts) have a significant performance advantage, when they're appropriate. For example, you can fit 2x as many floats into cache compare to a double and good cache behaviour is really important these days, it's one of the reasons languages like C/C++/Rust with good control over memory layout can be very fast. Also, you can operate on 2x as many floats with vectorised instructions; again, SIMD is important these days, especially for things like games (where the precision of a float is fine).