Doubt on jenkins

Hii ,I have a question is like… why root user is getting assign instead of jenkins user??

What so you mean with

the concern is when tasks or operations that should ideally be carried out by the Jenkins user end up being executed by the root user instead.

Jenkins will start things under the user it is itself running when it runs on the controller. Or as the user the agent is running as. Jenkins does not perform user switching.
So it seems you’re running Jenkins as root user which is always a bad idea. And when you install Jenkins as rpm under Linux or you use the standard docker image Jenkins will not run as root but as user jenkins.