And there is nothing to stop you from using messenger if you like.I would also be fine with this.
For all of Facebook's many flaws, the Messenger app is way more fully featured than iMessage and it is, for better or worse, the preferred option for my family and friends for large group chats. Our "Family" Messenger chat goes constantly all day long with parents, grandparents, grandchildren, kids, spouses, etc. Only 1 person in that chat is on an Android device.
The reality is that the SMS standard as part of GSM messaging simply doesn’t support such functions. that is not a limitation of the client it is what the standard supports.