At first blush, it could appear that the "COE" (Chief-of-Everything) is exactly the same thing as a "solopreneur". However, that is not the case. While there are some similarities between the two, there are some important differences.
Solopreneurs are individuals who operate their own businesses without any employees. They often work as freelancers or independent contractors, providing their skills and services to clients on a project-by-project basis. They are responsible for all aspects of their business, including finding and acquiring new clients, managing finances and administration, and continuously improving their skills and knowledge.
Acquiring new clients often involves networking, building relationships, and promoting their services. They also need to negotiate contracts, manage projects, and handle their own taxes and legal requirements.
The main distinguishing trait of a solopreneur is that they are working on their own. Having to do multiple tasks is a consequence that stems from working alone.
The COE also takes care of many different things, but the COE is not necessarily alone. A COE is at times the head of a small company, or perhaps a department head even in a large company. The COE can delegate tasks, insource or outsource. Being a COE is not necessarily about doing, it is more about responsibility and taking ownership.
I would say that a solopreneur is a COE due to the nature of working alone, but a COE is not necessarily a solopreneur. Although there may be some similarities, the two concepts are not the same.