When engineering teams build distributed systems, they naturally reach for REST over HTTP/1.1 with JSON payloads. JSON is readable, universally supported, and trivially easy to debug with any browser or proxy tool. For early-stage services handling modest traffic, that convenience is a genuine engineering asset. But as microservice topologies scale toward hundreds of nodes handling tens of thousands of concurrent requests, text-based serialization frequently evolves from a minor convenience into a measurable architectural bottleneck. CPU utilization climbs, p99 latencies widen, and intra-zone bandwidth costs quietly compound across every internal service hop.