CICD isn't an alternative to testing your own work locally. You should always validate your work before committing. But then once you do, the CICD pipeline runs to run the tests on the automation server and kicks off deployments to your dev environment. This shows everyone else that the change is good without everyone having to pull down your changes and validate it themselves. The CICD pipeline also provides operational readiness since a properly set up pipeline can be pointed to a new environment to recreate everything without manual setup. This is essential for timely disaster recovery.

If you're just working on little projects by yourself, it's usually not worth the time. But if you're working in anything approaching enterprise grade software, CICD is a must.