It was never designed to solve parallel installability problem.… which is exactly why it causes version hell.
Could you expand on that? Since a modular system currently
prevents parallel version installation, it may provide
suboptimal/obsolete versions, but I wouldn't tap it as 'version
hell', which in my mind describes a system with multiple installed
versions installed all over the place, causing confusion and
uncertainty as to the ABI compatibility and patching status.
Perhaps you are saying that a hypothetical system allowing packaged parallel installed versions provides the authoritative registry that tracks such dependencies, and therefore does not have these problems?