they can be harder on the engine than a supercharger.
Superchargers are harder on the engine and the powertrain due to the reasons you cited. The sudden shock at launch on the whole system is the biggest culprit.
The issue is I would rather have say a 6.4L or 6.5L that produces 500hp or better than supercharge an engine to get it as you always have that power.
Yes, but you can have a 6.5L that is already very strong to take this kind of abuse and add an induction system to it and have a real monster.
For example, if the belt was removed from the supercharger
Then engine would not work since there is no way to get it air to the intake.