Let's assess this logically.

[Zabuza]

So how do you explain this difference? They are cutting their profits purposely or what?

As of April of 2019, SE had created one new data center for NA and EU, as well as expanding their server infrastructure. https://na.finalfantasyxiv.com/lodes...d1ebf675536bb9

COVID started sweeping through the world not too long after that, at which procuring servers became increasingly difficult. Whatever the reason, I doubt they purposefully cut into their own profits to stick it to non-Japanese players.