It could change something if we forced them to compete on how much of CO2 they emit for MWh.
Too big to fail is a terrible direction to move towards.
The main superpower that companies have is that they can die and be replaced by others doing better.
A carbon tax basically does this but at an economy-wide level, and allows us to play off fossil fuel companies against EV companies, rather than just playing off Shell vs BP, for instance.
(Concrete production uses petrochemicals as chemicals, not as fuel. Well, often as fuel too, but…)
In my mind that would be dramatically better for a ton of reasons.
More competition.
Less ability to hire huge legal teams.
Less ability to influence elections.
Less ability to influence laws and regulation.
And those things would make it easier for us to force them to cut their greenhouse emissions.
It's also completely burying the lede: the actual reported data at hand is the line still going up, and states increasingly account for the increase compared to "real" companies which are on a downturn. Which is kinda but not specifically related to exactly how many boardrooms are involved.