It is plenty useful when you are recording, and don't know what the peaks might be, or the troughs - you try to get the amplitude centered on your dynamic range window - but you might have it wrong! - one peak too high and the recording is toast - a trough too low, and it gets lost in the noise floor...
An extra 20db is a very valuable commodity!
Also when ripping / archiving vinyl... sadly the pops/clicks are very large in magnitude - so you have to allow circa 20db above what you expect the peaks of the recording to be, to allow for those - as if the pop / click goes over the 0.5db point then the distortion impacts the entire frequency range...
Once recorded cleanly you can process it, delete the clicks/pops, and adjust the levels - so you record in 24bit even though 16bit (96db dynamic range) would be more than ample... in a perfect world you would record using 32 bit giving you dynamic range of a theoretical 1500db (!?!) - 24 bit is supposed to be 144db in theory - but as you can see looking at specs, it is very rare to find an ADC that even achieves 120db.
But yes - beyond 120db is useful in various recording processes... but not so much in playback - and quite ironically, we can achieve 130db in playback, but usually barely get to 110db in recording!
