[anjakefala]

I think the argument is that for non-scientific usecases, folks don't really need to think about error or significant digits. By focusing on the significand too much laypeople aren't grasping how large and small these numbers are relative to each other.

It's not being put forward as a recommended tool for scientists when reasoning about precise values. It's put forward for laypeople when trying to understand the vastness of the universe.

[vanderZwan]

Yes, that was my take-away too. I suspect it's a wonderful way of teaching intuition for differences in scale, which is something that's a lot more important to us today than it was a few centuries ago. Easy mental guesstimates should not be underestimated as a valuable tool