Why is public school better than homeschooling?

I am home schooled on my computer with a program called CAVA (California Virtual Academies) they have a program with k12 an online homeschooling program. With CAVA you have your own teacher, and you have class sessions too where you can video chat with the teacher and other students. Home schooling is more academically challenging. Thats why its a better option then public school.