"For the $47.10/metric ton carbon capture cost, 48% comes from CAPEX while the remaining is OPEX. The equipment life of a carbon capture unit would be similar to that of a power plant, about 20-30 years. The $47.10/metric ton cost is just for carbon capture, and does not include transportation and sequestration costs."
I look at it as one of many possible conventions for communicating precision. For what it is, it works well. But it's not universal, and people who do and don't use it should both keep in mind that the other group exists.
Mark with a chalk.
Cut with an axe.
(Apparent practice at a workshop I used to frequent.)
Tolerance? H7.
The fitters threw a fit trying to make that happen.
Tracking precision through calculations requires interval arithmetic, which is a pretty big PITA and not frequently used.
I think the sig figs cult comes out of mistaking a simplified lesson on precision for a useful practice.
Checkout https://en.wikipedia.org/wiki/Interval_arithmetic for what it takes to monitor precision through complex calculations (in particular, see the bits about using the taylor expansions of non-trivial functions).
Why $47.10 and not $47.1032471?
It shows a lack of understanding of either basic science or napkin maths.
For either reality, science or invention, it matters.