Google’s Rich Communication Services is a modern protocol that seeks to replace SMS/MMS, which has been in use for decades. The green bubbles an iPhone user sees in certain chats is indicating not that the message is coming from an Android user, but that it’s being sent over SMS.
The more updated RCS protocol allows for many features that SMS doesn’t, including read receipts, the ability to see when someone else is typing, and the option to edit, rename, and remove yourself from group chats. With RCS, you can also share high-res photos and videos — a noticeable flaw with SMS between iPhone and Android users.
However, the most important feature RCS has is end-to-end encryption. SMS lacks this, which makes communicating over the platform much less secure. By refusing to adopt RCS, Apple is consequently making texting less secure for all people using SMS to communicate with non-iOS users. While Google and Samsung may use green bubbles as an easy way to goad Apple into adopting RCS, increased security (among other features) may end up being the stronger argument.
It remains unclear if Apple will join RCS, but there’s another way green bubbles may go extinct. European regulators are currently debating whether to mandate that Apple offer iMessage on non-Apple devices under the Digital Markets Act, which requires interoperability between “core platform services.” For now, though, you can expect more campaigns like Samsung’s most recent video.