This is all true, and if you read the KEPs they were thinking about this. One camp was advocating for solving the problem of specifying the full dependency grap

This is all true, and if you read the KEPs they were thinking about this. One camp was advocating for solving the problem of specifying the full dependency graph spec (of which sidecars are one case), another advocating for just solving the most needed case with a sidecar-specific solution to get a solution shipped. The latter was complicated by a desire to at least leave the door open for the former. Pragmatism won out, thankfully IMO. Edit to add: see this better description from one of the senior k8s maintainers: https://news.ycombinator.com/item?id=36666359 https://news.ycombinator.com/item?id=36666359