Explanation/Reference:
Layer 7 load balancing benefits include:
Needs only a single IP address.

Inspects content and can direct traffic.

Provides notification of failed service that can be taken offline.

Handles load balancer SSL termination.

Distributes traffic at the application layer and understands the destination URL.
From scenario:
Load balancing must support the following functionalities:

Provide SSL termination

Remove failed Mailbox servers from the server pool.

Data collected by Managed Availability from Outlook on the web must be used.

Target server health must be configured as per-protocol so that only the affected client protocol is

directed to another server if a server fails.
References: https://docs.microsoft.com/en-us/exchange/architecture/client-access/load-balancing