Having been in the military, I find it hilarious and accept that it is not a place everyone should be. The recruiter likely has a very similar realistic understanding of where the military stands with people right now.
My power comes from the two sets of solar panels and batteries on my land. It is possible to do without fossil fuels. We’re not there yet for everyone, but the problems you point out are solvable, and if solar/EVs had the same amount of backing from the government over the same timeframe that gas/ICE cars have had, we would be in a very different place right now.
There is no current game I want to play that doesn’t run on Linux. Valve really has done an amazing job with proton and getting games to work as well or better on Linux.
Now, that said, I am not big into competitive multiplayer, so take that into account. Anti cheat is still a problem since most of the current ones need permissions that are not normally given on Linux.