The Cost & Risk of SwitchingWide moat

The switching costs that keep TSMC's customers in place are among the highest in any industry, and they are multi-dimensional. Moving a leading-edge design from TSMC to another foundry would require re-engineering the chip for a different process with different design rules — a massive, expensive undertaking of many months or years. It would carry the risk that the new foundry's yields and reliability fall short, jeopardizing the product. It would mean re-qualifying the design, potentially missing a market window worth far more than any manufacturing savings. And it would mean rebuilding around a different, thinner ecosystem of tools and IP.

Worst of all, the customer would be switching to an inferior process — trading TSMC's leading edge for a rival a generation or more behind. For a company whose entire competitiveness rests on having the best chip, accepting a worse process to escape TSMC is close to unthinkable; it would mean shipping a product that loses to competitors who stayed with TSMC. The combination — enormous redesign cost, real execution risk, schedule delay, ecosystem loss, and an inferior end result — makes switching not merely expensive but strategically self-defeating while TSMC leads. This is why the leading customers have stayed generation after generation: the switching cost is not just money, it is competitiveness itself, and no rational designer trades a winning chip for a losing one to change suppliers. The lock-in is enforced by the customer's own self-interest — and by arithmetic: with 90%-plus of leading-edge output at TSMC, there is scarcely anywhere else to go¹.