Proxy doesn’t mean substituting for something you already own, it means something standing in place of or representing something else. In the case of mtg, people use proxy cards to stand in for cards that they don’t want to spend hundreds, thousands, or hundreds of thousands of dollars on but want to play with casually
I’ve been to game stores that allowed proxy play as long as you had the original card. (For FnM)
They usually had the same rule for foreign language cards.
Presumably the store wants you to buy cards that you don’t have from them, yeah. But luckily that isn’t a universal rule.
It’s a way to drive business for sure.
I did love the foreign language card rule though because all the game stores near me don’t have that rule and there’s assholes that run full kanji decks so you end up having to sit there with your phone pulling up each card they play if you can’t remember each mechanic on the card etc. And since the matches have a time limit they use it to win by default.
Foreign language cards are entirely legal in official competition. I bought many of my dual colour lands on eBay from a German dude. Always passed deck inspection. Granted that’s literally over 20 years ago and I never placed higher than 17th in qualifiers, but I can’t imagine they changed that rule.
