I have no experience with SMS other than as an average user. I'd love to know from someone more knowledgable than me, how secure this would be? From my basic un

I have no experience with SMS other than as an average user. I'd love to know from someone more knowledgable than me, how secure this would be? From my basic understanding it seems that SMS would be hard to intercept on the phone network, but if a site is using an SMS gateway, it's not much safer than using email for two factor auth, right?