Now a question daunted on me. Assuming away strategies like store-and-decrypt-later-in-a-quantum-future, could a MITM really eavesdrop, as in, aren’t such ARPA-

Now a question daunted on me. Assuming away strategies like store-and-decrypt-later-in-a-quantum-future, could a MITM really eavesdrop, as in, aren’t such ARPA-routed phone calls encrypted?