I think it all comes down to this (my personal understanding):
The HS knows that the physical incarnation is just temporary adventure of one of its consciousness fragments (you).
It knows that the physical world is also complete illusion, a simulator.
For the immortal eternal HS none of the stuff that happens in the physical universe is of major concern in the end.
It knows that no one and nothing gets out “alive” out of the physical universe.
What is of major concern for the HS though, is the growth of consciousness experienced while doing the simulator adventure.
Growth of consciousness comes from making experiences and from having realizations.
But also from developing real free will and making your own decisions independent of circumstances, which then also leads to the skill of manifesting your own reality.
You can only manifest what you want when you are aware. And when you have ability to choose and decide.
So my answer would be that it all comes down to the HS wanting you to reach certain realizations, primarily through observation, self-reflection and experience.
Illnesses are just tools to come to certain realizations.
The HS is mostly very detached with that.
An incarnation into the physical is simply a fragment of the HS “jumping into cold water and let’s see what happens”.
It may feel absolutely real to the fragment being inside that cold water, but the HS knows that it is just an experiment and an interesting experience.
About people developing diseases:
With enough developed intuition and conceptual realizations skill, one can skip the painful parts and go straight to the realizations.
Aka “learn the lesson” without the “need to escalate”.
When people do not listen to their intuition or “act mindlessly”, situations in the simulator escalate to illness and other bad experiences.
This applies to most cases but not all of course.
The HS also wants you to develop free will.
Also, if the HS would intervene all the time, how could you ever develop real free will?
Free will is like a muscle that needs to be trained.
And what better way to train it, than under the harsh conditions of the physical simulator?
And why is real free will so important?
Because the ability to love UNCONDITIONALLY can only come from a true free will decision.
Otherwise you simply cannot love.
And the ability to love is for sure a godlike skill that most HS want to develop.
PS:
I am also curious to hear Psychic Universities’ answer and view on this.