What about having savings instead of "investor funding" ? If you have developed a great product why in the world would you like to share your company with VCs a

What about having savings instead of "investor funding" ? If you have developed a great product why in the world would you like to share your company with VCs anyway ? Why you need somebody to invest in your company ? I mean come on people, you can save $10k in vacation as a college student waiting tables and have 100% pie for yourself. I don't understand the logic here. Never did.