If only it were so simple.
“Input” doesn’t work because sometimes the signal goes from socket to plug - in the case of a 1/4” audio cable, both ends of the cable plug into identical sockets, one of which is an input and the other is an output.
“plug” and “socket” are closer but still not a perfect universal replacement for “male” and “female” for connectors. For 1/4” connectors, “plug” and “socket” work fine, but consider XLR (the standard connector for professional microphones). With XLR, there are two types of plugs and two types of sockets. Audio sources have “male” sockets and sinks have “female” sockets, and cables typically have a different type of plug on either end.
I don’t think the sex metaphor will disappear unless another, more inclusive metaphor which clearly communicates that distinction arises to take its place. “Source-type” and “sink-type” might work, but takes a bit more explanation and learning to understand.
