The real reason is that there's no 32-bit floating point digital audio converters, so distributing the audio in a format which needs to be quantized to be played anyway has no purpose (outside of deceptive marketing, of course).
Even integer 32 bit makes no sense for a final format - the available noise floor is just beyond reasonable, 24 bit is more than enough. In practice, 16 bit is too.
The real reason is that there's no 32-bit floating point digital audio converters, so distributing the audio in a format which needs to be quantized to be played anyway has no purpose (outside of deceptive marketing, of course).
Even integer 32 bit makes no sense for a final format - the available noise floor is just beyond reasonable, 24 bit is more than enough. In practice, 16 bit is too.