I find putting http proxies in containers to be a very effective method of building interesting dynamic L7 dataplanes on orchestrators like k8s. Packaging applications (particularly modern static SPAs), with a webserver embedded, is also a very intuitive way of plugging them into the leaves of this topology while abstracting away a lot of the connectivity policy from the app.

Of course there's also the well-known correlation between the quality of your k8s deployment and the number of proxies it hosts. /s