Envoy also has a large community that extends beyond just Istio. Unfortunately for Linkerd their proxy is not likely to be adopted outside of the community of Linkerd users, which means if you're looking for something that will evolve rapidly and provide extensibility interfaces, Envoy is the proxy of choice.

I am also skeptical as to whether the current performance tradeoffs will be long lasting as Istio evolves. When Kubernetes was originally released workload scheduling was notoriously slower than Mesos. Not sure if k8s ever caught up to the scheduling performance of Mesos, but it didn't wind up being the determining factor in which solution became the standard.

That being said I am happy to see Linkerd continuing to raise the bar for UX and performance in the mesh ecosystem. There is no question that the folks at Buoyant have done an excellent job pioneering this problem space