I was privileged enough to trek to Kangchendzonga back in 2002, well before it was a WHS.
It was a genuine wilderness experience at that time - nothing like the teahouse treks you experience in Nepal.
It was a real adventure with the scariest part being an early morning trek to viewpoint in darkness. On the return journey, it became clear that we walked on slippery glacial moraine above a very long drop!
It was a truly wonderful experience and well worth the 5 stars. I do hope that the climate crisis is not completely destroying its natural beauty.