The Sidecar Tax: Why eBPF Reshapes Kubernetes Observability Economics in 2026

Service mesh adoption in Kubernetes hit a critical inflection point in 2025 when teams discovered they were paying substantial CPU and memory costs—up to 50 vCPUs per 500 pods—for Envoy sidecars that merely observe traffic. eBPF shifts observability from the pod layer to the Linux kernel itself, eliminating per-pod overhead while maintaining full network visibility. This architectural rethink, powered by tools like Cilium and Hubble, is becoming the economic baseline for enterprise Kubernetes deployments in 2026.