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Pre-ordering games made sense in the days of physical media when there was a very real chance that your local game store might not have enough copies in stock to meet demand and you might not get the game for days or possibly weeks
Pre-ordering a game that's in beta so you can get early access, help test shit, give feedback, or just experience a thing while it's being built makes sense. It's not for everyone but some people enjoy doing this, as a sort of community participation.
Preordering a mainline pokemon game is pants on head retarded