Why does one of my "text-mates" text come across as an RCS message?

[FF22]

I have a variety of TEXT chats going on in the Google Message app but only one seems to take the form of an RCS chat. I don't know if I care that much but am curious why just this one person and I have created this RCS chain. Is there someway to return this to a normal chat or just start a new chat thread? Should I want all my chats to be "protected" and be in the RCS format? And I guess what would have triggered this behavior so I can either initiate it if I want or NOT initiate it?

 

[B. Diddy]

If both people on the messaging thread have RCS chat features enabled, then the thread is RCS. The other people who you're texting with presumably either have iPhones or have not activated chat features on their Android phones (and if those Android phones are really old, then RCS probably isn't available for them).

RCS is more secure than regular SMS due to end-to-end encryption. For the people in your chats who have Android phones, ask them if their chat features are turned on. For the people in your chats with iPhones, there's no option besides using SMS because Apple.