WIY I disagree. There is a motivation/image issue that holds back a lot of donateable funds from going to black hole tzedakos and schools as you mentioned. But when there is a real connection between donor and cause and deployment of funds, there is much more money available. For example, when the Mir yeshiva needed funds to stay open a year or so back, a person whom I work closely with dissolved a trust to make a big pledge. His precise words at the time were along the lines of this money makes a difference so I will buy a legacy right away instead of after 120. I was also inspired to send money that was earmarked for something else. Neither of us has shaychus to Mir, and we would both do it again for a cause like that.
There is so much money in the hands of people who believe in and support torah. But donors are sophisticated and want their money to be used well.