[labcomputer]

Actually, it does. You can decimate the higher sample rate to increase dynamic range and S/N ratio.

Also, for direct down conversion, you can get better mirror frequency rejection by oversampling and filtering in software.

[Etheryte]

None of this changes the actual real amount of data you have at the end of the day though after all is said and done, that's what I mean, so long as you don't botch it and capture too little. In computing terms, the amount of real data in a compressed archive and the uncompressed original is the same, even if the file size is larger for the latter.