That’s because your mobile plans are usually different and you get charged for each SMS, while SMS is typically included for free in mobile plans in the US. Since you have to pay per SMS, people instead use WhatsApp and Signal which don’t have a per message charge.

Let’s be patient with this and not give him a hard time. For those of you who haven’t used Sync before, there was a major update a while back which caused strong emotions from many people and caused the developer to take a hiatus. Please be patient and kind and the result will be worth it!