Modern pandemic response planning in the U.S. got its start in the Bush 43 administration, focused initially on the emergence of a deadlier-than-normal flu strain, which is of course a respiratory disease. The Obama administration continued this work and applied it to outbreaks of SARS, MERS, and Ebola.
The Trump administration failed to staff, fund, and prioritize that work at the same level.
There is tremendous leverage at the beginning of a pandemic, but it dissipates quickly. That’s why continuous planning and preparation are so important.
By the time the Trump administration got serious about the response, it was too late, they had lost most of that leverage. Most of the things people argue about now—lockdowns, school closures, mask mandates, etc.—happened well after that point.