Children with special needs are an exception, because it’s often the case that their tremendous needs can only be met in the public school setting. Otherwise, it’s simply too big a risk to take. Work with the tuition committee, and get Rabbanim involved to help negotiate an affordable rate.
It is true that, years ago, attending public school was commonplace. However, public school is not what it was in the 1920’s when Rav Gifter, ZT”L, attended through age 13. At an Agudah Convention in the late 1980’s, Rav Gifter told about the time when he said a minor expletive in class, and the public school teacher promptly washed his mouth out with soap! Needless to say, it’s not like that today!