There are a few potential disadvantages to hiring freelancers for web development:
1) Quality and consistency of work may be inconsistent, as freelancers may be working on multiple projects simultaneously.
2) Freelancers may have difficulty staying up-to-date with the latest web development technologies and trends.
3) Communication can be more difficult, as there is often a communication barrier between the freelancer and client.
4) It can be more difficult to find qualified freelancers than it is to find employees.
On the other hand, there are many advantages to hiring a web development agency. Perhaps the most important advantage is that agencies have a team of experts who can work on your project. This means that you don't have to hire a designer, developer, and project manager separately - which can be expensive and time-consuming.
Agencies also have years of experience in web development, so they know how to create beautiful and user-friendly websites that rank well in search engines. They also understand the latest trends in web design and technology, which means your website will be up-to-date with the latest trends.
Finally, website development agencies offer a range of services such as web design, SEO, online marketing, and social media marketing.