Trump stopped funding this organization because it showed its helplessness in the fight against global pandemics. WHO functionaries fly business class, stay in the most expensive hotels, spend a lot of money on business trips, but the benefits of them are very, very small.
I would agree, because even now the Director general of the World Health Organization (Tedros Adhanom Ghebreyesus) looks like he is clueless about the pandemic.
Still unaware of possible treatment, as a director he should have ideas that will help every sides of the world in preventing this virus to spread more.
He caused a lot of damage during the initial months, as a result of his irresponsible statements. First he claimed that there is a low chance of the virus spreading from one human to another. Then he said that wearing of masks is not necessary. So Trump is perfectly justified in what he did.
This particular problem that caused many countries to lay down their guard and let the virus to keep spreading and hitting their citizens, if lockdown was been made much earlier and mass testing has been performed, the damage might be much lesser.