I'd much rather have someone who understands people and how to organize and construct a team actually lead a team than someone who has mostly technical skills being the leader of a group.
In my experience, it's signficantly easier to teach a technical person some management skills than it is to teach a manager some technical skills. That's an experience based on doing it myself and working under/with quite a few of them.
Sure, it shouldn't be a huge department, but there is value.
This is the key part. Human civilization needs a little of everything, and there is absolutely value in having some people who specialize in very niche topics. Some amazing things come from the study of niches topics, even in social studies. But we absolutely don't need thousands upon thousands of people who are experts in the same niche, because it's a niche.
Average scuba tanks are 21% O2 by volume, matching the atmosphere, but may be other ratios depending on the task at hand. You can use a 100% O2 tank safely down to 6 m, at which point the risk of seizure from oxygen toxicity becomes too high for most.
Not exactly. the gas inside the tank is 21% (or whatever you want, really), but don't forget the tank itself it also very heavy and quite bulky, especially when adding all the other equipment.
The devil finds work for idle circuits to do.