(unless a complete working solution is presented in that other technology, and as long as that other technology still creates MSI files with free-as-in-beer tools).
Just out of interest, what's the reason for enforcing that the installer must be an MSI? Or, rather, if I were to present an alternative .exe installer that ticks all of the above boxes, exceeds the capabilities of the current installer and above all is easier to extend and maintain -- would that be a non-starter because it's not an MSI?
Not necessarily - it is just very hard to provide the same features as MSI, but with a different tool. It seems that most tools have given up the battle against MSI, and now provide just another layer on top of MSI (just as my msilib does, or WiX).