Antithesis and Jepsen want to kill hand-wavy "high availability" talk. Instead, they push for clear availability models—majority, total, sticky, etc.—that spell out when an operation actually works during failures. It's about precision, not platitudes.

Why it matters: This reframes availability from a vague uptime promise to sharp, per-request conditions. Way more useful when designing fault-tolerant, distributed systems that do more than just seem alive.