I've seen people try, only for it to never actually work (images either compress horribly, to the point there's no reason even sending it, or just fail to send).

MMS bring broken since day 1 in my experience is probably the reason I jumped on internet chat and email, since those actually work as advertised (sure, they has some practical limits, but they tell you about those!). I probably would have sent my mum that image over MMS if MMS actually every worked. Since it never did, using a difference service was a must.

Then again, this feels like an extension of the rest of the phone system. Anything beyond calls between two people, SMS and data that involves connecting to the phone system has always (in my experience) been either janky or broken. No wonder I try to use anything else given the opportunity.