Expanding on why humans don’t do this (as often) the fleshy part of our ears is functional. Depending on how sound bounces in your brain can determine some additional features that it couldn’t just from two ears. If I recall correctly variation in ear shape between people also creates difficulty in creating identical universal 360 sound. Can’t help but find it fascinating we’ve had ray traced games for a bit now but sound is mostly still just faked and not simulated.