Hi @tsloughter 
I am generally of the opinion of having fewer applications as part of Erlang/OTP. With build tools and package managers available, I would leave concerns such as httpd to the community. 
For httpc, I would focus on lower-level process-based abstractions. Think gen_http. This solves long-standing problems in other HTTP clients, which do impose an architecture and often end-up incurring additional performance costs (and more binary references). This is a design we explored with Mint. You can still provide high-level functions that open up the connection and perform a request but without the pooling bits (which the community could build on top of).
I am almost sure this is the default and correctly done on Erlang/OTP 26.