Our starting point is decentralization, isn't it? So, isn't it too narrow-minded to habitually think that everything must be on a blockchain?

Security and trustlessness are the core objectives of decentralization. Decentralization is not an end in itself, but a means to enhance and move away from centralized control. Emphasizing the means over the core objectives is to miss the point.

Perhaps it shouldn't be called blockchain gaming, but rather decentralized gaming, just as in the social sector, where Farcaster and Ceramic are intriguing because they don't fall into fixed patterns of thinking, but rather consider things from their fundamental starting point.