Ok well here is a general longevity-related reason why resistance training is important.

Lifting weights also increases bone mass. As you get older, osteoporosis becomes more and more of a concern. You fall one day, and the less bone mass you have built up, the more likely it is that you will lose mobility. There is a strong link between reduced mobility and cognitive decline and also a cascade of other health problems. Old person + hip fracture = significantly increased mortality, and the way to prevent this is by building up bone mass while you still can.