The author here is making a mistake that happens a lot with this kind of situation: conflating effectiveness with overreaction. He cites to infection rates leveling off in other countries, but fails to consider the fact that they've also implemented significant restrictions. China lowered its own infection rate by basically closing an entire province, and it seems to have worked. Italy is now seeing the start of a leveling-off as well, and that's about 2 weeks after putting the whole country on lockdown. The comparison to South Korea is also inapt, given that they reacted much faster and more prudently than the US did.
On the death rate: there are three problems here. The first is that his number is wrong; the WHO estimates a fatality rate of 3.4% worldwide, not 1%. Next, he conveniently leaves out Italy, which has seen a fatality rate of 5%. At least part of this is attributed to an overwhelmed healthcare system: in China's case, the death rate was 5.8% in Wuhan province, but only 0.7% in the rest of the country. Finally, 1% is still far from insignificant. If we had half the country infected, which is on the lower end of the estimates I've seen for doing nothing, a 1% death rate means 1.8 million people. That is a lot.
As for the economic impact, it's the usual "think of the job creators" nonsense. He's right that the economic impacts will be significant, but why is it only a choice between accepting a few (hundred) thousand more deaths from COVID-19 and trying to return to business as usual? If nothing else, the last few months should be showing us just how unsustainable our current economic system actually is. Shocks like disease are inevitable, and if our system is too brittle to handle them, it deserves to fail. If we'd listened to progressives 10 years ago, we'd already have measures in place that would've handled the economic effects far more effectively.