One of the main reasons behind the push for RCS adoption is that RCS can transmit high quality images, much higher than MMS. Soon, the most popular RCS app on Android, Google Messages, will get the ability to send original quality photos.
It's a new setting in the Photo Selector, the button that says HD or HD+. Not the most informative name, but once you tap it, you get more descriptive options: one reduces the size (and quality) of the image, the other sends photos at original quality (at the expense of using more data). This was discovered by Android Authority team while destroying the beta APK for Messages.
OK, even though “HD or HD+” is a bit vague, at least the words will be familiar to users – these are the same buttons that WhatsApp uses.
New image quality for sending photos via Google Message
Last year, Google Messages got support for send Ultra HDR images via RCS. Ultra HDR, introduced with Android 14, combines standard JPEGs with additional metadata. Software that doesn't support it only views JPEGs. Software that supports it uses metadata to recreate the wider dynamic range of the original HDR image (more detail Here).
Again, this button is available in the beta version of Google Messages, but will be rolling out to the stable release soon.