Separate rotor support and gearbox?
Every helicopter has components that must not fail in flight if disaster is to be avoided. It would appear that minimising these would be a desirable design goal.
It seems that it might not be essential to include pretty much the entire gearbox in the list of these critical components. Clearly any gearbox failure is likely to result in a loss of drive and a subsequent autorotation, however there seems no essential need to combine the gearbox with the support of the main rotor as seems to be commonly done.
The two EC225 crashes may have had a better outcome if these functions were separated.
I am fairly sure for example the the Robinson R22 separates the reduction gearbox (belts:-) from the rotor support structure.
It may of course be more challenging to arrange a 3,000HP helicopter that way as opposed to the 100HP Robinson but I don't see that it would be impossible or even impractical.