Answer:
mistakes
Step-by-step explanation:
The main disadvantage would simply be "mistakes". Since it is your project, you are the one who has the vision of what it is supposed to be and what it is supposed to accomplish. If another individual is responsible for actions such as purchasing and managing technical equipment and staffing, they could make the mistake of buying the wrong equipment or hiring staff that is not necessarily suited to be part of the team. These are all mistakes that can be easily made if the individual in charge of these responsibilities does not have all the individual details of what the project is supposed to be.