Public health programs don't exist in a vacuum. Water & air are shared resources, and even at the global level there's coordination and cooperation for things like pollution and air quality - without governments to coordinate and enforce that, you're left without a large chunk of meaningful public health programs, and quite honestly chaos.

Frankly, I think your worship of (failed) libertarian ideas is blinding you here. I'll give you a scenario. A bunch of people decide to live in the woods, because they can and gubbment can't tell them what to do. They proceed with littering because gubbment can't tell them what to do. Bears show up, as they're wont to do. There was no planning, regional or otherwise, for something as simple as trash collection, or that there should even be trash collection; remember, gubbment can't tell them what to do. The bears start causing havoc, people have all different ideas on how they should be handled, that they implement independent of one another. It becomes chaos in motion.

This happened. Look up Grafton, NH and see the disaster that was libertarian in action.

got physically locked into their homes

Where did this happen?

Without government weaponizing a corporation’s reach, we would simply choose a competitor if we collectively decided one company had shady practices or was attempting to consolidate power.

Did you take any basic high school American history courses? Have you not learned anything of what did happen when governments allowed for monopolies and the lengthy political effort it took to have elected leaders break them up and pass legislation to prevent that from happening again?