Both testings are necessary, but one needs to be aware of when to make use of the right one. In my opinion, automation testing should be used in the following:
Your project can have a lot of content, and the testing runs a long time. Automation can help you to do it faster. However, in small projects where the testing phase runs for only a few weeks, Manual testing is preferable.
Is your product instability and has a long list of test cases? Automation can help you to do it faster.
Automated scripts help to make considerably effortless Regression testing.
Automation will help to improve business efficiency. It might help you https://u-tor.com/services/automation-testing