This doesn't seem to be universally and objectively true. The nation overall has about 30 ICU beds and 20 ventilators per 100,000 people. In states were the disease outbreak is out of control, such as N. and S. Dakota, they are reporting 300-400 new cases per 100k people per day, 5-10 new deaths per 100k people per day, and hospital occupancy of 25 per 100k for COVID-19 alone, and rapidly increasing.
Therefore, we must have a consistent policy within that border if we ever hope to get this under control.
Or we need to set up internal borders, which is quite against the constitution.
The federal government imposing nationwide lockdowns on each and every state is a gross overreach and completely unconstitutional. It's not an easily solved problem in the US system of government. We're a free country, or at least we pretend to be.
Edit: This seems to be causing some confusion. OP is referring to the need to have "consistent policy across state borders."
AFAIK, it did no such thing. The federal government advised certain measures, and state and local governments (inconsistently) implemented stay at home orders, etc. based on their own authority.
You cannot bring cherries into california from almost all USA states (except AZ, NV, CO, and WY). I experienced this personally. The state border crossing took cherries from us while we crossed from Oregon, less than 3 months ago, and dumped the cherries in trash.
This is not limited to businesses, and is not a pandemic measure. This has been a long standing policy, meant to protect california's agriculture. Oh, the free trade exponent country has protectionism practiced by its states.
If South Dakota is running out of ICU beds, and Denver isn't, get them to Denver. Yeah, that's expensive... but is it nationwide lockdown expensive? Of course not.