tcely, > Messenger is a popular service so there’s presumably a not-insignificant amount of people that used the SMS/MMS integration to just have one messaging app. However, it’s likely not a core aim for the company anymore, especially with WhatsApp being the other big service it maintains. The deprecation is ultimately a win for Google and its continued RCS efforts.
https://9to5google.com/2023/08/07/facebook-messenger-sms/