Unless you are suggesting a teacher can clone themselves to however big their class size there is, the individualization is not a realistic prospect given that you have to teach a few dozen kids in a 30-45 minute period. And given that current funding levels are having a hard time keeping teacher retention even at these levels, significantly increasing teacher numbers to make real individualization possible is not within the realm of reality.

Also, individual teaching methods don’t work well in certain subjects; as an example, you need a few people to put on a theatrical production, perform ensemble music, or have Socratic discussions.