It sounds like the US took up a global cause on its own and when the clock ran out they didn't renew because that emergency had subsided.
Is this what was being pinned as Trump's "fault" in recent press and social media?
https://www.snopes.com/fact-check/trump-fire-pandemic-team/
The US used to pay for this because the downsides of not doing it are higher than the cost. Also, initiatives like these increase the US’s political and economic power overseas.
Indeed, the money that government disease detectives first tapped to fight the latest outbreak was a congressional fund created for health emergencies.
Some public health experts say a bigger concern than White House budgets is the steady erosion of a CDC grant program for state and local public health emergency preparedness — the front lines in detecting and battling new disease. But that decline was set in motion by a congressional budget measure that predates Trump." https://www.snopes.com/fact-check/trump-cut-cdc-budget/ The blame game is beyond getting old...it's moldy.
That's to prevent the current situation where in game theory terms, we're being the sucker and so it's in everyone else's best interest to leech. We need to reach a new nash equilibrium where everyone is contributing together (which is eventually more optimal for everyone involved, despite the short term hit).
I understand the need for assurance that those dollars are effectively working towards the intended goal, but assuming you are a sucker for paying the bill is only right if there was nothing of nutritional value to you in the menu.
So I guess the question is about working the data and crunching the numbers to know whether there is or isn't impact on your own economy and the welfare of your population, and not about not feeling like a sucker on the supranational ego scene.