> Sharing a video via group MMS is fraught with problems, it often doesn't work, or the resolution is garbage.

FYI, this is carrier related. Many carriers have a hard limit on how big attachments are, and will silently reject them if you go over that limit.

What the limit is varies based on the carrier, but it seems that a "safe" limit is ~1.1 MB (This is the hard limit that Android enforces for the largest MMS attachment it allows). T-Mobile seems to allow higher (I think I got up to 10 MB?), but I do not know what would happen if you sent an MMS to another carrier that is that big (they probably silenty drop it).

So you have two options: either reduce how big it is (which Android Messaging silently does), or flat our reject it. So the video is problem is silently reencoded to accomedate the 1.1 MB limit.

Why doesn't this happen on iMessage? Probably because you can set your MMSC (the Server that sends/recieves MMS) to Apple's MMSC, so you can standardise how big it is.