[nonameiguess]

In addition to whether or not all of your various dev teams preferred languages have a supported client SDK, you also have the build vs. buy issue if you're plugging COTS applications into your service mesh, there is no way to force a third party vendor to reengineer their application specifically for you.

This probably dictates a lot of Google's famous "not invented here" behavior, but most organizations can't afford to just write their entire toolchain from scratch and need to use applications developed by third parties.