The reason people use helium is so they can do deep dives to 250 feet plus and not experience the toxic effects of O2 at that depth. Also at shallower depths say around 180 feet helium is great because you do not experience the narcotic effect O2 gives you at that depth. Something that is kind of important if you are working at depths.
It's part of using the right tool for the job. All I am wondering is when using film developer for paper is using the "right" tool.
Hey I'm a crankie old bastard and proud of it, damit! Just ask Aggie.