I have plenty to of friends and family who use various Android and iPhone and have never heard people complain. They are all able to text and send each other media. Im not doubting it is an issue but just speaking from my experience that I havent heard it be an issue from people know
Speaking for myself, if someone is a person I consider a friend or a family member I want to contact, I will find a way regardless of phone choice and I think anyone would
People still do have issues when the sender and receiver are on two differ carriers. Sometimes a multi media doesn't go through, is shown too small, cut off, or linked instead of showing within the message. iMessage and other 3rd party messaging services stay compatible.
I completely agree with your last statement though.