Initially, it was considered to replace TCP with QUIC and use HTTP/2 as an overlying protocol, but the differences between TCP and QUIC were too large, so a new HTTP version exclusively for QUIC ...

TCP is the building block for Layer 7 protocols, such as the HTTP. This chapter will examine the interaction between HTTP and TCP and how client and server communication at the TCP and HTTP layers are ...

While TCP (or TCP/IP) is your virtual network, you still need the physical network -- what's inside that "cloud" -- to support the protocols. Listen to the SAN FAQ audiocast here.