Some people have disabilities or physical limitations.
It is pretty obvious the grandparent comment was just attempting to give a generalized advice, without claiming that it would comprehensively apply to every single niche condition out there (and it would be rather silly to expect it to).
Exercise is even more important if you have a disability, because your muscles will atrophy from disuse and cause even greater disability.
E.g. if you stop moving your leg because you have a bad knee, you will now have a bad knee and a weak leg. If you go to PT and do exercises to strengthen the muscles around the knee, it can take load off the joint and improve function.
I broke my arm late last year in NYC pretty badly, ended up having to get a surgery for carpal tunnel release + a titanium plate implanted.
Doctor told me I needed to do physical therapy for a few months after the surgery (which made perfect sense, because I could barely move/rotate my wrist, no finger/grip strength, and my mobility range was abysmal).
I searched for a reputable PT place nearby that was accepting new patients and that was a member of the American Society of Hand Therapists (per my doctor's recommendation), scheduled an appointment for the week after, gave them my employer's insurance info, and that was it. I never had to interact with the insurance company throughout the entire process, and they covered it just fine.
I know it is anecdotal, but out of my friends who deal with PT way more often than me (typically those who are seriously into competitive team sports), I am yet to hear of a differing experience either.
Insurance said: you get four sessions total. But you can pay the rest out of pocket.
For my parent it was a bit better, they covered all the sessions but only max of 30 minutes per day. My parent at the time was in mid 80s so could not rush through it so quick, needed like an hour. Therapist was forced to leave after 30 min and leave some instructions to do the other half alone.
But hey, insurance company CxOs got some nice fat bonuses, so that's all that matters!
But plenty of people with very disabling conditions became those world class athletes, or live life where they use their bodies to the extent they can. I bet it is because they have found a way to move they truly love. If you do something you like doing, you do it more.
Nobody claimed otherwise.
Nobody is telling someone who physically can't run to run. There is no reason to interpret it this way.
It truly is a bizarre spin on whataboutism.
> How about you instead of trying to “get away with” as little exercise as possible you found a way to move your body that you genuinely enjoy? One should not optimise away sleep, nutrition and exercise.
Answer: because exercise can be physically very painful, impossible, or sometimes dangerous for people with certain medical conditions. Knowing how much is enough can be useful to know without being shamed for “optimizing” away exercise.
Hope that helps. Pointing out that people with different situations exist to a generalizing comment should not cause such offense, imho.