In the beginning of a startup journey, it's "all hands on deck". People do everything that needs to be done, learning as they go. But what does each person really want to do? What are they good at? Are these roles compatible? What's missing?
When you grow, you will need to hire people. You might even end up hiring your own bosses, if that's what it takes for the company to succeed. That will surely cause some growing pains when outside expertise meets the experts that built this particular company.
Making sure roles and responsibilities are discussed openly and honestly is a key factor in startup success, and can prevent disillusionment when changes inevitably happen.