Messages are processed faster as they are in a binary format compared to text. Since they are in the native binary format over the wire, they don't need to translate from text to binary by the TCP protocol.
Binary messages
Header compression
As the web has evolved, more data is sent from the server to the client and from the client to the server. HTTP 1.1 does not compress header fields. HTTP works over TCP and a request is sent over this connection, where the headers are large and contain redundant data. TCP works on Slow Start implemented by a network congestion-avoidance algorithm, which places packets over the network. If the headers are compressed, more packets can be sent over the wire. HTTP/2 fixed this problem...