Except that SMS messages can be intercepted, e.g. by having a proper access to the SS7 backbone, by abusing services provided for other reasons, or by SIM swapp

Except that SMS messages can be intercepted, e.g. by having a proper access to the SS7 backbone, by abusing services provided for other reasons, or by SIM swapping attacks. All of this has already been done, so it's not just theory. See e.g. https://arstechnica.com/information-technology/2021/03/16-attack-let-hacker-intercept-a-t-mobile-users-text-messages/ https://arstechnica.com/information-technology/2021/03/16-at..., https://arstechnica.com/information-technology/2017/05/thieves-drain-2fa-protected-bank-accounts-by-abusing-ss7-routing-protocol/ https://arstechnica.com/information-technology/2017/05/thiev..., https://arstechnica.com/information-technology/2016/08/congressman-to-fcc-fix-phone-network-flaw-that-allows-eavesdropping/ https://arstechnica.com/information-technology/2016/08/congr...