Yes. There are no current browsers that implement HTTP/1.1 pipelining, and even various proxies and others don't support HTTP/1.1 due to head of line blocking and proxy errors.
Also, with HTTP/1.1 pipelining if a client sends multiple requests but one of the requests results in an error and the server closing the connection all of those other requests are lost.
Also, with HTTP/1.1 pipelining if a client sends multiple requests but one of the requests results in an error and the server closing the connection all of those other requests are lost.