The good thing about SMS is that it's standard. I live in Sweden, just about everyone has a smartphone. SMS is still common for things like package delivery not

The good thing about SMS is that it's standard. I live in Sweden, just about everyone has a smartphone. SMS is still common for things like package delivery notifications or other service notifications, SMS is still an option for many transport tickets, though being phased out in favor of app solutions. SMS works whether you're on iOS or Android, it works for the few users of classic phones, it works if you don't currently have mobile data, etc. It's not a secure method of communication and has other flaws, but it's the most reliable one if you don't know anything about the recipient. Whether they're using their beloved Siemens S35 or the latest Android flagship, they can receive a SMS.