A trillion bucks is a lot of money. The costs of shutting down the economy are larger. California's GDP is essentially zero at the moment. US GDP was about $22 trillion per year before the virus hit, almost $2 trillion per month.
Shutting everything down and staying home for a few weeks is a sledgehammer. OK, our leaders have to hit a virus with a sledgehammer when they have nothing else up their sleeve. But it cannot last. Businesses will close, people will lose jobs, the economy will not be there to start up again.
Needed fast: a plan to open up the economy again in a virus-safe way. Every business should be (and likely is) working hard to figure out how to operate in a virus-safe way. Federal state and local government need to be working 24 hours a day during the next few weeks to promulgate virus-safe practices. Not because they are particularly good at it, but because they are the ones shutting things down, and their permission is needed to reopen, fully or partly. People also will want the confidence to know that businesses they patronize are compliant. You've got two weeks -- figure out what combination of personal distancing, self-isolation, testing, cleaning, etc. will allow each kind of business to reopen, at least partially.
The option to force everyone to stay home and close all "non-essential" business for three or six months is simply not viable, at least for a disease something short of the bubonic plague. The option to wait two or three weeks and then start thinking about what it takes to allow, say, the local dry cleaner to reopen, which will take another month or so, is simply not viable.
Take two weeks. Find out who has it and who doesn't. Test test test. Isolate, put out the embers. And reopen. Slowly, cautiously, partly. But reopen.
I have kept public health and economics separate, but they no longer are. Shutting down the economy is a public health measure. The costs of this measure are astronomical -- at least a trillion dollars per month. As yourself what the government could have done with a trillion dollars to nip this in the bud. Please, next time, be ready. Massive testing, identifying cases, contact tracing, isolating areas with known cases, early and hard might have cost a lot of money and disruption. Even 100 billion dollars now looks like a very small sledgehammer.