[Idea] Live track via SMS?

SMS could be sent via our phones

Not on iPhone's ... Apple hasn't provided an API to send messages that way.

The only way is to replace iPhone by Android

If I can text android users from iPhone, why wouldn’t this be possible, just out of curiosity?

As @fallingrock wrote, it's impossible and it's guilt of Apple. They haven't provided necessary code for application developers and those programmers from Garmin can not write a code, that makes Garmin Connect App send SMS with Live track link.

But it's still possible on Android!

They haven't provided necessary code for application developers and those programmers from Garmin can not write a code, that makes Garmin Connect App send SMS with Live track link.

But they will definitely sell you an Apple watch that can do this

Bull's eye :) That's a point

If you subscribe to Strava - their live track does SMS but that's because it's sent by Strava on the server side. So for Garmin to do this, would need it to be sent from the Garmin servers not the phone

Most (if not all) SMS numbers have an equivalent email.  For example, for AT&T phones, the email is "phonenumber"@txt.att.net.  Just use that instead of the person's real email id.  Their service provider will then send them an SMS.

This is true, and works pretty nicely. It is, though, only available to paying subscribers.