Have you received transactional SMS messages before? How important do you think they are for customer communication?

Transactional SMS messages always seemed like something only big companies used, but I started looking into them after a recommendation from a colleague in Croatia. I found a great explanation of what is transactional sms and learned that theyre not just for banks and e-commerce sites. They can also be used for appointment reminders, order confirmations, and security alerts. I had no idea how useful they could be, and now Im thinking about implementing them in my own work.