Override template purpose

I’m sorry if this questions sounds stupid, but I found no explanation here.

I was reading the documentation https://docs.villatheme.com/woocommerce-email-template-customizer/#configuration_menu_6559 but I couldn’t understand the purpose of creating/copying the templates from the plugin installation folder to the active theme.

I understand that copying templates from Woocommerce main folder to the child-theme prevents from losing the customization when Woo updates.

What’s the point of creating this “email-template-customizer” folder and copying from your main folder to this sub-folder theme?

Thanks!