IOS 18 finally supports RCS for imessage.
Yes it does, and here’s how it works once you’ve upgraded iOS 18,
simply open up the settings app,
find messages, and then select RCS Messaging.
After this is turned on,
when you send or receive messages from a device like a Google Pixel,
both phones will support read receipts,
typing indicators and and high RES image files.
And the text bubbles are still displayed as green.
But honestly, that doesn’t matter at all
as long as the features are there to deliver an equal experience
no matter what device you’re using.