Why do software companies test outsourcing?

I think there are the following possibilities:

1. Software testing is a special software project process. If the demand for software is high, the software testing department is needed to control the quality, but the software testing department also has achievements. If it is built internally, it may cause "entanglement" on some specific quality problems, such as impersonality, difficulty in control, competition between testers and R&D personnel, etc.

2. For many projects, Party A requires Party B to issue credible quality control reports, and testing is one of them. If this credible testing process is established internally, it will have a profound impact on the organizational structure and development. It is better to outsource directly, so that the test results are objective, the cost is controlled, and the organizational structure and decision-making methods are relatively simple, killing two birds with one stone.

3. From the perspective of testing specialty, outsourced projects can also get better support. If an enterprise has many projects, it is better to outsource this link to raise a group of testers, which makes it easier to control the project cost.

My humble opinion is for reference only.