The current economy is a factor, for sure. But even before the crisis, it was normal for only 40% of the parent body to pay full (from Yated Chinuch Roundtable), let alone the number of students.
Now of course, that is because tuition is way too high for anyone with a “normal” income + large family to pay. But you do choose to have a “normal” income (lets say high 5 figures) and choose to have a large family (Al Pi Halacha, no doubt).
There may be very good reasons for not paying in full, but it still does not solve (and even explains) the problem of the schools having no money.