Back when (I started) we carried our spare ammo in 'loops'. Brass casings would gunk up quickly, think summer with temps and humidity both in the upper 90s. I had a Sargent that didn't care much for 'guns'. His 'brass' 38s froze in the chamber of his S&W Model 15 (it could have been a Model 10).
Other than brass turning green when being poorly cared for, I see no functional difference or the need for nickle plated cases. Pre carbide sizing die, just about every sizing die for .38 Specials had picked up a carbon scraper. We lived with it on all of out re-loads.
Now a days, I'm sure I have some nickle cased some place. I don't buy them, don't see the need. Nickle rifle cases would look 'spiffy'.