MMS video file size has a default limit set by your provider. However, basically every phone has RCS available by default these days - which will be used in these cases automatically, within the same messages app - except when Apple refuses to allow it because of cross platform interaction.
You stated that iMessage provided this benefit, and it doesn’t; it isolates this benefit from being used. “Depends on the app” is just false. It’s “depends on the hardware” - google messages even recently expanded RCS support to phones that didn’t support it for one reason or another it in April. These data limitations haven’t been saving people from issues for over a decade, you’re conveying outdated takes.
You are literally falling for snake oil lmao