I renovated my house over the course of two years, so I've had a lot of close contact with tradespeople. Carpenters, demo, electricians, hvac, plasterers... the young guys are ok and buckstrong. By the time they're in their 40s, you can tell the work is rough on them.

Having muscle is only one dimension of fitness. You're entirely neglecting cardiovascular health, which is a better predictor of longevity.