It's not important to be strong. It's important to feel strong. This is what keeps humans going. Despair is insurmountable without self esteem, in some regard.
https://www.goodreads.com/quotes/256992-it-is-important-in-l...
eg If your limbs are disabled, being able to handle the resistance to a gentle ocean wave, is a way to feel stronger than you normally do.
Expecting that "being strong" will always mean the same thing (even within your own lifetime) is not rational.
>> There is but an insignificantly vanishingly small sliver of humanity too sick to strength train, even if it is just overhead pressing some cans of chicken noodle soup while you watch tv.