Not always more expensive
Based on personal experience, in June last year, Zurich-Mauritius in Business with Emirates via Dubai was the same price as non-stop with Air Mauritius (really one-stop outbound in Geneva, non-stop back) Special offer from the Dinarobin hotel.
Routings via third countries often produce very low C fares. A few years ago, I went from Geneva to Houston via London with BA, in Business (paid by my employer). A UK-based colleague joined the flight in London. His fare was triple mine.
Momo