What about supporting multiple versions of libraries at a computer? They all support it: npm, rvm, virtualenv, cargo, golang, python, maven and etc.

A very common use case is to use some newer version of something than what shipped with the OS but at the same time you don't want to potentially cause instability in the OS...

Or you know, developing multiple projects w/ different versions from a single OS.

Also in case I really want to do it, I have to go to some obscure website download some payload and read some build instructions to see how to best integrate to my messy CMake/Make system...

All of it could literally be replaced by something akin to

    cppvenv create myproject
    cppvenv --depend-on grpc-1.40 zeromq json
    cppvenv build