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. 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.
In addition, it is important to remember who supplied the Ebola vaccine to African countries a few years ago and how the who functionaries were indifferent.
Perhaps it was because of this indifference that the coronavirus was able to spread to the entire planet. If the threat had been announced earlier, many countries would have had time to close their borders.