Live Prompt: Should Checkout Be One Page or Multiple Steps?

A stakeholder tells you before the interview even starts: "Our checkout is five separate pages — cart, shipping address, shipping method, payment, review. A competitor just switched to a single-page checkout and their conversion went up. Should we do the same?"

1. Is this a well-formed design question as stated? What's missing that you'd need before answering "yes" or "no"?
2. Name the real trade-offs between a single-page and a multi-step checkout — not "single-page is modern," actual mechanisms.
3. Propose a concrete recommendation for a checkout that currently has a high payment-step-specific abandonment rate (as in the main case study) — would consolidating to one page help, hurt, or be orthogonal to that specific problem, and why?