We should learn why we would use such a feature, so the following points will illustrate why we use a VNet2VNet connection:

• Extending the virtual network communications to other regions, and subscriptions, which results in a well-connected, integrated environment for complicated applications.
• When using a VNet2VNet connection, you are using a VPN to enable the connection between them, which makes your connection more secure.
• When using virtual network peering across different subscriptions, you need to ensure that you have the required privilege for the other subscription. However, when using a VNet2VNet connection you do not have to, you only need some cooperation from the admin of the other subscription.