I wonder why white pepper is so underappreciated. My grandparents never had black pepper in their house. They considered it "foreign". White pepper is very distinctive and, because it's white, you can put it in béchamel sauces or mashed potato.
To a first approximation, white pepper is simply "peeled" black pepper (the peppercorns that are used to make white pepper are also harvested later, but apart from this, as far as I'm aware, the main difference is that white pepper contains only the inner seed). White pepper is spicier and misses some of the flavor notes of black pepper due to the removal of the skin, but otherwise they are not that dissimilar I think.
I thought white pepper was more common in the British empire - it's what I grew up having on the table. I still keep a bottle around - I feel like it's sweeter and spicier.