That observation doesn't justify all risks. To reduce to absurdity, clearly we shouldn't train for war by running war games in which soldiers actually shoot and kill each other, even though there's a compelling argument that this would probably be a very good way to maximize readiness...

IMO, the number of jumps the Army does each year is far in excess of what is necessary for readiness.

Do you have research or relevant expertise to back up that opinion? (It's fine if you don't; everyone is allowed to have opinions on any topic.)

No. I'm not sure how I would get that research, or if it's even possible. The problem with preparing for war is that war is fairly uncommon, and even when it happens, certain activities are rare enough with such a huge number of alternate causalities for failure that you might not have enough data for a useful natural experiment.

What I can say with some confidence is that there are perverse organizational incentives for some highly accident-prone training exercises. So, even if these exercises are required for readiness, that's not the (only) reason they're done in such high numbers.

>>>I'm not sure how I would get that research, or if it's even possible.

Military Operations Research is a huge field. I like to use Google Scholar, which has many Masters Theses from military grad students, etc... Here's a few results to walk you "on target" if you want to continue to dig:

https://apps.dtic.mil/sti/pdfs/ADA545145.pdf

https://apps.dtic.mil/sti/pdfs/ADA618622.pdf

https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=airb...