SMS is one of the different way to reach customers directly without caring about opening message rates or spam tools.
WhatsApp is one of the biggest channels used by entrepreneurs since the pandemic. We have noticed on some stores when customers bought some products, they didn't care about the email send and the newsletters, that's making they can miss a big deal or a promotion. To avoid it, what about using SMS or WhatsApp messages on your WooCommerce stores?
In add of sending emails, is not a good idea? ( don't you think? ), to send SMS or WhatsApp messages to let him know about the way his order is going, to let him know about next promotions he shouldn't miss or sometimes share some coupons code he can use. If you want to do all of this with SMS or WhatsApp messages, the plugin Ultimate SMS & WhatsApp Notifications for WooCommerce is the one you need on your store.