Everything you say is true about the demographic and political conundrum of 0bamacare. However, the GOP has had six years to figure a way out of the box. And they should have at least had a viable framework ready to roll out. They get in power and it turns out they have nothing. It appears it was empty rhetoric in pursuit of power. And maybe that’s all it ever was.
There's probably no way out of the box, since it's tied to a demographic distortion that isn't a political issue that can be fixed.