It honestly is far from wasteful actually. You will receive responses in the same thread, collected as part of the discussion/messaging. Sure, you can point and say, "Why don't you use <insert third party app like Slack for instance>?" but the only necessity for entry is simply to possess a phone with group MMS capability. No extra app needed. No extreme workaround required. Group the people that you want to send and share the conversation. I use group MMS to broadcast to many people one item that would only be replaced with sending 10 people the same damn message over and over. Now that's wasteful. Having to convince friends to install an app; equally wasteful to me.