Offtopic:
The way i view it is learning about Japanese culture and their practices, its not a sin to learn about other cultures and religions (please correct me if I'm wrong on this), so why would it be to learn them through video games? The more i know about other religions the more it makes me feel better about Islam tbh.
Regarding this in particular. Starting from 90s kids tho its rare, but defy starting from Gen Z people are playing games more and more while justifying it as "learning".
It really isnt. Dont deceive yourself brother. Or should I say more like, dont let satan deceive you. You call it learning, so have you taken notes? Delved into more content types than just games, like have you read books, watched documentaries, or watched historical videos, like what have you done to actually learn it other than just sticking to playing games where most of the time spent is not even learning but rather spending in the game mechanics like completing missions which is the point of the game to begin with.
Narrated Ibn `Abbas: The Prophet (ﷺ) said: "There are two blessings that many people are deceived into losing: health and free time."
Sahih al-Bukhari 6412
Not necessarily giving you any fatwa to play games or not. Whichever you lean, be mindful of your free time. Some people feel learning these makes their Emaan grow stronger. That is oxymoron. Someone with a strong Emaan wont be wanting to spend countless hours playing games WHILE not spending much time to read the Quran or Sunnah so they learn what Allah is telling them to make life better.
And scholars generally agree that one shouldnt expose themselves to haraam materials if they dont have knowledge of the deen. So be mindful of how you spend your time.