Remember - it's not an "investment" when the asset doesn't exist physically, and will stop existing in a couple of years when Duel Links ceases to be profitable and they switch off the servers forever.
Now I understand why everyone has been using more or less the same decks against me. I may have been playing against the same players all the time due to smaller player base after Zexal World release.
that's not the reason, ppl hate pvp, they play only to get kog & for that they will use the best decks (tier 1) after they got their title, they switch for other decks, so to have fun, reach KOG than u will enjoy duel links,