Clean energy transitions are cheaper than the fossil-fueled path we are currently on

cheaper doesnt mean implementation if the capitalists will lose profit.

the united states could save a huge amount of money by switching to universal healthcare, but that would kill several lines of profit, so it wont ever happen.

That's no surprise, and entirely irrelevant.

The US political system is broken. It doesn't legislate according to what is thought to be best for the country or its people - it legislates according to what will bring the most money from wealthy individuals, corporations and interest groups.

Fossil fuel corporations and industry groups have very deep pockets and have well-established channels by which to funnel that money into the hands of politicians, party officials, and assorted powermongers, so the government is going to generally legislate in their favor, entirely regardless of any other considerations.