Why should the site show the user the number of requests and the time spent on this?

Question

Web development

In many sites, in the footer I see messages of this kind: 51 queries in 0.689 seconds
What does this give an ordinary visitor, and why is it needed at all?

Answer 1

This is generally for developers and admins rather. And it is useless and even harmful for users to know this.
I understand if you still show it in debug mode or for authorized admins who are members of the group, and so empty bragging.

Answer 2

This is debug information not for the user, just lazy people do not remove it