Which would be fine if we had something like COM to enable portable interfacing between libraries and certain level of separation, especially when a library plo

Which would be fine if we had something like COM to enable portable interfacing between libraries and certain level of separation, especially when a library plonks something breaking your runtime by messing with global resources (for example, threads and signals). But we don't, and the libraries push other issues into your design as you often are forced to follow their specific idiosyncracies.