I was going to leave this as a comment on the Ian McKellen debate, but it turned out too long:
Almost everything is contained in one sentence: "I imagined what it would be like to be a wizard, and then I pretended and acted in that way on the day." How much more simple can you make it, than to say great acting (or great pretending) is joining imagination to action? The Craft is to do that well, and all the techniques and methods are accretions upon that simple idea - one that is somehow so easy for some (the talented) and yet harder for others. For most of us, it isn't hard to use our imaginations. The tough part is in the joining. So people need all sorts of techniques to help them leap across the divide from solitary, internal experience to deeds that give and share the being inside. Perhaps why we love great actors is that they appear to have mastered making the jump from "me" to "us". That's something everyone wants, except maybe monks, and even they live in communities.
But as the focus of actor-based entertainments (films, plays, tv shows) has shifted from a style more overtly based on archetypes to what we call "realism", the actor's training has become more therapeutic. Learning to be an actor no longer simply requires mastering the artful deployment of gestures, facial expressions, and vocal tones as required by the "type" the actor is playing. It means being a like "real person" with "real experiences". So the actor joins his own actual internal life to the internal life of some imagined person, and then displays to the world the results of that inward mixup. There is an amazing "Apocalypse Now"-parody scene toward the end of "Tropic Thunder", where the Robert Downey Jr. character is removing all the stuff he has worn portraying a black Vietnam-era sergeant. As he removes the wig and the mustache, and drops the accent, he regresses backward through various characters he has played over the years. And when he finally reaches his own voice, he looks up and says, "I don't know who I am."
One reason why I like your idea/ideal of acting that "gives" is that it implies its contrary - an acting that "takes". Now I don't think they are in perfect symmetry - the "giving" acting gives to the audience, whereas I think acting that "takes" is this therapeutic form of the craft of acting, in which the actor uses their portrayal of the character to fill some inward void - or worse: deepen it. The "filling" is what the Downey Jr. character was getting at. So I think the Method exists, and will continue to exist, because it recognizes something about the psychology of a lot of actors. They are drawn to the profession out of some profound psychic neediness and sometimes even self-loathing. They see that emptiness or lack filled up by public acclaim or approval for becoming something other than they are. And the Method says, "You've got pain? Great! Use it to become someone else." But that's a lie. We can only become who we are. But we can pretend to be someone else.
And to make sure Anne's comment is brought to light:
I imagine that techniques of acting come in and out of fashion in synch with cultural changes. The Method must have been very powerful for a generation that had trouble accessing their feelings. In our era of weepy Oprah segments, I would expect actors face very different cultural challenges to the ideal of intellectual/emotional/physical clarity and expressiveness. But even now, the Method is just the ticket for some individual actors.
And beyond either of those considerations is the question of what kind of play you're in. New writing may require new acting styles, and therefore new approaches to training actors.
It would be remarkably silly to ignore the historical power and significance of what we call The Method, but we all need to agree that it is really just A Method.