I occasionally cut calories to lose weight or train my metabolism to be "ready" for emergency situations (which was honestly camping or going broke, not exactly military excursions), but in my experience it basically felt like death. Like I could feel my body catabolizing muscle and I had flu-like symptoms if I took it too far for too many weeks.
Anecdotally, my parents' boomer generation felt that bodybuilding was generally a waste of time. If you watch old movies from the 60s and 70s, people were especially lean. And then unfortunately juicers in the 70s, 80s and 90s ruined the reputation of bodybuilding so everyone figured that being strong meant taking steroids. It's only been in the last 5-10 years or so that I've noticed a resurgence in natural bodybuilding (check out Jeff Nippard, Steve Cook and Mike O'Hearn for examples of what's possible natty).
So personally I really feel that lifting weights from about 15-16 years of age for life probably replicates many of the health effects of calorie restriction. Like, Arnold Schwarzenegger did some of his best work in his 40s when he was in better shape than most people in their 20s. Many athletes in their 70s and 80s look like they're 50.
An untrained human bench presses about 100 pounds. When I was growing up, a 300 pound bench was considered mastery. Today with YouTube and better workout programs and supplements, that's probably 400-500 pounds. I personally would choose to have 3-5 times average strength (anything above 4 is metahuman IMHO) rather than spend my life at a withered calorie restricted strength of 1/2.
Of course ethically, it would be better for the planet if nobody worked out I guess. That's a separate discussion though, and I feel that some of the downside could be alleviated if the extra calories came from relatively benign sources like rice and beans. So my question is, is this all just vanity? Or would a diet/exercise approach be comparable to calorie restriction?