Pretty easy answer, at least from my viewpoint. 20 years ago, ships were not the destination. Carnival decided not to follow the lead (they never really ever followed RCCL by nature), RCCL was paying way more for their mega ships and the return was obviously not there for Carnival. The Excel class is/was a perfect for the next generation of Carnival ships (personally, from my take they could have made 8 more Vista class an I would have been overjoyed….but they did not ask me 😏). Covid, altered life for everyone and for the cruise industry as well, and especially Carnival Corp. With their significant pause for the debt structure payoff, revenue generation needs changed, the ships as the destination increased (partly due to covid residual affects), and the investment for private islands/resorts exploded. Just my view, but did not require a ton of thought and fits perfectly with all of their press and marketing over the time.