Better a 5% chance it does good than a 100% chance it's squandered on bureaucracy and inefficient solutions to problems other tax dollars went to creating.
Whatever ethical questions may lie in forming a "charity" with an unknown level of veracity, there are also ethical questions in giving the money to an organization that will, without a doubt, surveil, imprison, torture, and murder.
...is today's version of "down with the capitalist dogs; long live the proletariat and glorious socialism!" of eras past.
Global capitalism taken to its extreme is an ideology that promotes a massive transfer of power to private individuals and the dismantling of the state. Libertarianism, in other words. Unfortunately, utopian ideologies have a nasty habit of becoming tyrannical dystopias when put into real-world practice.
Extreme capitalist ideology paints government as cartoonishly hopeless and inefficient, maybe even evil, run by inept bunglers that steal our money and waste it on paperclips and perks for bureaucrats. The solution, they say, is let private for-profit business take over and watch efficiency skyrocket and costs plummet. Sounds wonderful...except it's a hopelessly naive utopian fantasy (or, depending on your outlook, a scam to transfer even more power and wealth to the world's billionaires).
My own view is that unfettered capitalism taken to its logical conclusion will result in a feudal society...or violent revolution.
Total revenue for the federal government was about $3 trillion in 2014. You don't think that the American people got at least $150 billion in value out of that?
After all, there's absolutely no chance that you are able to choose people to do thankless tasks upon which your life depends (disposing of sewage, supplying potable water, maintaining roads, ...).