One point most people seem to have missed is that "benefits" such as use of gym, free healthcare, dental and eyecare are not primarily designed to benefit the individual they are there because the Service requires that we are fit enough to deploy.
It would be nice to think they were available purely because they would be useful, but if that were the case then spouses/dependants would be entitled to the same healthcare/dental.
The reality however is keep a serviceperson fit and well you can use them as you see fit, hence the investment is neccessary.