Yeah, I really tried to cover a part of how it's so bad in my post. It's really something from a different time. There's a lot of the old WAP 1.0 kind of thinking where the carrier ran their own proxy to make the content consumable by the end device due to limitations at the time. If you don't fetch the content off the MMSC in time it expires. I know there's lots of RCS spam complaints, but the carriers ran email to MMS gateways that had abuse for years.
Verizon had the wackiest system with their vtext service where it really tried to customize more than the GSM carriers and they ran their own web portal. When they phased that out a few years ago it broke picture scaling for pretty much all non-iphone devices on their network. This is another big reason I wanted working RCS because if I send a picture to Android users on Verizon it ends up scaled down.
Verizon had the wackiest system with their vtext service where it really tried to customize more than the GSM carriers and they ran their own web portal. When they phased that out a few years ago it broke picture scaling for pretty much all non-iphone devices on their network. This is another big reason I wanted working RCS because if I send a picture to Android users on Verizon it ends up scaled down.