I don't see why it should be subsidized with taxes.

I don't see why 0.2% of the annual budget should be a focus of cost concerns. The total expenditure in the 2024 Federal budget was $538 billion dollars. If we subtract the cost of Canada Post from that it would be... About $538 billion dollars.

If this was a private company, they'd be willing to work it out because they'd be afraid of the business folding

That goes for the business refusing to negotiate with the union. If it was a private company they wouldn't have the option of waiting until the government forces everyone back to work without an agreement.