I could not agree with your points more enthusiastically. I also take the view that polyamory is more expansive than what the mainstream media makes it out to be - EVERYONE who loves more than one human being in any way is practicing polyamory, but our culture doesn't educate us about how to communicate authentically and kindly, or how to have good relationships IN GENERAL, so everything is a mess.
And yes, it at least just as much about intimacy and support as it is about dating and sex - and for many people, it's more about those first two things than anything else.
The advances in communication, honesty, and self-awareness required to make poly relationships work are the same things that make mono relationship work. We just don't pursue them as a society because a) it requires hard, uncomfortable self-work, and b) the monogamous paradigm falsely claims to protect you from all the pitfalls of human relationships, and people buy into it because that messaging is force-fed to them from birth.
We've got a lot of work to do. I'm so grateful there are people like you out there speaking the truth!