The NetworkWatcherRG resource group is automatically created by Azure when you enable Network Watcher in your Azure subscription. Network Watcher is a regional service that enables you to monitor and diagnose conditions at a network scenario level in, to, and from Azure.
The NetworkWatcherRG resource group contains the Network Watcher resources for each region in your subscription where Network Watcher is enabled. Each Network Watcher resource is responsible for network diagnostic and visualization tools in its region.
If you delete the NetworkWatcherRG resource group, it will disable Network Watcher for your subscription. This means that you'll lose access to the network diagnostic and visualization tools provided by Network Watcher in Azure, which could impact your ability to monitor and troubleshoot network-related issues in your Azure services. However, it won't directly impact the operation of your Azure services unless they rely on Network Watcher for their functionality.
If you don't need Network Watcher's capabilities, you can safely delete the NetworkWatcherRG resource group. But if you're using Network Watcher for network diagnostics and visualization, you should keep it.