The networking overhead of serial requests would be reduced by multiplexing in Http2, i.e., multiple http requests/responses can reuse the same tcp connection in parallel...
Multiplexing is completely different from keep-alive. With http2 a web browser requires one tcp connection per website as communication is in parallel, approaches like conncatenating several css files into one have no use with http2 anymore! Http1 keep-alive allows reusing the same tcp connection for sequential requests/responses only.
