Yes, online classes are as effective as offline classes because people still learn the same stuff. A lot of what people learn takes minutes or seconds. The hard part is analytical thinking, such as computer science and novel writing. Those are the things that education has a hard time teaching.
Students cannot interact with teachers in online classes. There is no way for teachers to tell if students are absent or if they are paying attention if classes are conducted on the Internet. Real classes must be in real classrooms where people can actually interact with each other. Online classes are not realistic.