The decision is about responsibility
A business owner can spend hours learning marketing while still being responsible for staffing, appointments and customers. Doing the work personally avoids a service fee, but it does not make the time free. If learning and maintaining the website repeatedly displaces work only the owner can do, the apparent savings can have a real business cost.
For example, a contractor may enjoy managing a simple website but have little time during a busy project. Another owner may already have someone on staff who understands the site. Those circumstances lead to different sensible choices.
A freelancer can fit a defined assignment
A freelancer is an individual provider. That arrangement can work well when the business understands the assignment and knows who will handle everything outside it. A person hired to resolve a website problem is not automatically responsible for photography, advertising or every future update.
Freelancers offer different combinations of specialist work and ongoing support. A clear service list explains the assignment, communication and updates included in the arrangement.
An agency has its own advantages and limits
An agency can coordinate several skills through one relationship. That can be useful when you want website work, content and reporting organized with one point of contact.
The size of the company tells you less than the actual people doing the work and the person responsible for answering questions. A clear contact and understandable reporting matter in any arrangement.
Ownership should remain understandable
The website, domain and Google accounts each have access settings. An agreement that identifies ownership and handover makes those arrangements clear.
Account access and handover belong in the service agreement. A company should be able to explain access, handover and ongoing subscriptions in ordinary language. Unclear ownership can make changing providers unnecessarily difficult later.
Judge the arrangement by business value
SEO is used to bring leads to your business through search. Ask how the provider reports the work and the calls or appointment requests recorded for your company.
The right arrangement can change as the business grows. What works for an owner with one simple site may be unsuitable for a larger company with several teams. Choose an accountable relationship and a realistic workload, rather than assume an agency is always best or doing everything yourself is always cheaper.