A Forwarding Plan is especially useful when you have bought various domains for the same website. It is fairly normal to wish to protect your brand and to have the same name with various extensions (.com, .es, .shop). In these cases, it is very normal to have a single page on the main domain and to forward the other domain to the main one.
Another option is to forward our domain to a website that is hosted on a free space provided to you, for example, by your ADSL provider.