Service mesh adoption in Kubernetes hit a wall in 2025. Not because teams stopped wanting visibility, but because the bill arrived. Every pod in an Istio cluster runs two containers: your application and an Envoy proxy. That proxy consumes 0.5 vCPU and 50MB of memory at idle, before a single request arrives. At 100 pods, you are paying for 50 idle vCPUs that do no application work. At 500 pods, you are running 4-5 extra EC2 nodes purely to keep proxies alive. eBPF solves this by moving observability out of the pod and into the kernel. One program runs per node and observes all pod traffic from a single hook point. The pod count becomes irrelevant. That architectural shift is what makes tools like Cilium, Hubble, and Pixie compelling in 2026. The Sidecar Overhead Is Not an Edge Case: It Is the Default Envoy proxy overhead is not a bug or a misconfiguration. It is the intended architecture. Every pod in an Istio mesh gets a sidecar injected by a mutating admission webhook before scheduling.…