That's not really true and it depends on what you mean. If your decimal datatype has the same number of bits it's not more accurate than base 2 floats. This is often hidden because many decimal implementations aren't 64 bit but 128 bit or more. But what it can do is exactly represent base 10 numbers which is not a requirement for a lot of applications.
You can use floats everywhere where you don't need numbers to be base 10. With base 2 floats the operations couldn't be more accurate given the limit of 64 bits. But if you write f64 x = 0.1;
and one assumes that the computer somehow stored 0.1
inside x they already made a wrong assumption. 0.1 can't be converted into a float because it's a periodic in base 2. A very very pedantic compiler wouldn't even let you compile that and force you to pick a value that actually can be represented.
Down the rabbit hole: https://zeta.one/floats-are-not-inaccurate/
Not only for audio, but everything that doesn't have to be an exact base 10 representation (like money). Anything that represents something "analog" or "measured" is perfectly fine to store in a float. Temperature, humidity, windspeed, car velocity, rocket acceleration, etc. Calculations with floats are perfectly accurate and given the same bit length are as accurate as decimal types. The only thing they can't do is exactly(!) represent base 10 decimals but for a very large amount of applications that doesn't matter.