The 8th house is not always taken as you described.
Let me add something more to your knowledge.
This house also defines longivity, insurance,hereditary property,obstacles etc etc.
These all attributes falls under physical plane.
What you are saying is in mental plane(world of thoughts) and spiritual planes.
You will understand this only if you have gone through advance portion of
vedic texts.These planes migrates with the age and experience of a person.
For example.buying a luxury car which is in physical shape will be on physical plane whereas feeling enjoyment of drive is different and its pleasure is on mental level,
when your thoughts are active.Spiritualism plane is last plane when you have gone through physical and mental planes.
Next coming to your question, link of jupitor with 8th house leads to rebirth, soul liberation etc.See, jupitor is natural 9th house and 12th house lord in natal chart. Ninth house represents father,guru,blessings of elders etc and twelfth house represents moksha, sex ,foreign relation etc. Jupitor is lord of both the houses.Essence of both of these houses are served as per planes.
4th 8th and 12th houses are all moksha or liberation houses taking natural chart of aries ascendant.You have to understand it from basics.