Completely agree. This is common functionality in many other applications. I know it as “In-Line Editing”. It is definitely a time saver and makes the user more productive. For example, if I’m working with a list of contact names, and I see that a phone number needs to be corrected (or even added), I should be able to do that from right in the list without having to open the contact record to do so. This would apply to many other fields in the list as well.
I encourage you to add this basic capability as soon as possible.