For what it's worth, I overwhelmingly agree that Boost should have compression as a first-class library.
zlib comes preinstalled on most Linux distros. If anything, zlib is more popular than the Boost library collection in terms of the number of installs. So I'm not sure what you're going on about. The "bread-and-butter functionality that developers actually need on a day-to-day basis" is already abundantly available.
Our specific requirement is to statically link _our_ preferred version of zlib built from _our_ pristine (and possibly patched) repo. There is no build reproducability via system packages that get patched over time, or are pinned to a historical version for the purpose of system stability. But, building and linking a boost-bundled zlib would be pretty close to that, and pretty workable in terms of bringing our patches on top. - Nigel