Means testing won't fly because it's hard, or it's politically intractable?

You could test income (investment, or otherwise), as an example. Is that intractable? If politically so, then tough cookies, these cuts are necessary, we're not making this stuff up.

You could also REWARD people publicly for deferring their payments... Perhaps provide some benefit to a future generation/estate for people who opt out.

I'm not remotely pretending to be a wonk on these issues. I only see people unwilling to touch the "3rd rail" and I am desperately searching for brave candidates to support with my vote.
_________________________
The charm of fishing is that it is the pursuit of what is elusive but attainable, a perpetual series of occasions for hope. -John Buchan