I'll choose to get an investor because I don't yet have experience running a profitable business with positive cash flow. By finding an investor, I must prepare a pitch deck, which forces me to continuously improve and verify my ideas. I also learn how to convince investors. This is a very good experience. So, besides getting a cash injection , I can learn more about the potential of my ideas because I need to convince investors by answering their concerns.
That is actually quite smart but how hard could it be to try and learn things by yourself first before trying to bring in other people to meddle with your own business? Consultants are okay but once you start bringing people in that could alter the direction of your business, it might become too complicated.
There is no shame in being a beginner and learning how things work first and maybe even making a few mistakes. Seems better than letting the decisions be ran by other people who might even do some work before your back.