What's the use of templates?

I made a template in excel and I made an edit in the template, and it did not reflect in the pages that inherit from this template.

My first question is: is this the behavior of the template? In other words, if I change the template, it does not reflect in the inheriting pages?

My second question is: if the first question is true, what is the use of templates in the first place, in other words, why can't a simple copy and paste do the trick?

You cannot change a template & change existing pages created from the earlier version.

http://excel-it.com/excel_templates.htm

... in other words, why can't a simple copy and paste do the trick...
A template is meant to be a blank form.
Suppose that you create this dazzling, wonderful new "form" and save it as a regular .xls file with the day's info. Next day you open the file, delete yesterday's info and enter today's and save the file --- Oops, you forget to change the name of the file to today's date using save as... . Now the boss is looking for yesterdays file with yesterday's info!

Making a blank form and saving as a .xlt will always open the file as a blank and force you to give it a new name.

By the way, ancestors don't inherit from offspring. The arrow of time goes foward to the future, not back into history.