You understand that all business activity in an economy is driven by consumers. Everything is downstream of consumer demand.

Then, subsidize everything for all businesses?

Consumers are already paying heavy taxes for defense, trillions of dollars/year to protect business interests of the super rich everywhere.

What does this have to do with internalizing costs to businesses? By your logic, the government should just subsidize all consumer goods... Which, okay maybe I actually agree with you? (Jk I'm not that much of a socialist. I think markets are great, and we should leverage them by fully pricing externalities like road damage or pollution, enabling the market to solve some of our big problems)

Consumer demand can still be distorted.

I said this in another comment:

Imagine if we subsidized things that were an orange colour. Market prices of orange things would go down and consumption of orange things would go up. It wouldn't make sense to say "this is helping the many people that consume orange things therefore it is good".