Well, sure, there's workarounds. But most people aren't going to be running a VPN. And the documentation for in-flight WiFi explicitly instructs you not to tak

Well, sure, there's workarounds. But most people aren't going to be running a VPN. And the documentation for in-flight WiFi explicitly instructs you not to take voice calls, out of consideration for other passengers. You wouldn't be out of line politely asking somebody to stop.