In the Netherlands, there are approximately 330,000 developers. You might think that there are plenty to choose from, but it can be difficult to find the one person with the right skills specifically for your organization or project. Every requirement you have for a candidate significantly reduces your search group. A good recruiter can help with this.
While investing in recruitment can be costly and time-consuming, it can result in finding that one developer or tester you need. Recruiters can find the right people and also support with creative solutions. They can look beyond critical requirements to expand the search group.
In practice, making matches often means taking people away from competitors. Bidding against each other results in increasingly expensive developers and requires an investment in retaining personnel. There is little point in investing in recruiting new people if they leave your organization. Developers themselves are becoming increasingly critical of company culture and opportunities for development, making it more difficult to retain staff.