By the time you start home schooling a five year old you have had 6 years plus your age of experience and education. No matter how good a "teacher" is they can not care like a biological teacher can. It's a job.
Absolutely! What seems to me the hardest thing about classroom teaching is finding out what each kid knows, how they think, what they are interested in and the best way to approach them. Then, somehow putting that into a "whole" that can reach each student.
Parents know these things about their own kids.