About a year ago on Wikipedia. I was deep in the rabbit hole clicking on this link and that link. It's one of those links I wished I've saved. I can't find it; I've tried. It showed a Spanish deck of 40 cards. Back then(13th or 14th century) 40 card decks were more popular then 52 card decks. Always, they played this game called "twenty-one". (K, Q, J, 7, 6, 5 ,4 ,3, 2, A) X 4 suits = 40 cards. The Ace could be 1 or 11. It had basically the same rules as modern "BlackJack". I thought, "Wow, this game is so much better than "BlackJack". It's so simple". What if you got a King and a Queen? that would be 19. I bet 40 card deck users thought, "Why would I want to add more cards. Do I want to play with 10 cards in a suit or 13 cards in a suit?
Then I found out in the beginning the Ace was not the highest card. The Ace has been the highest for only the past 200 years. Cards are roughly 600 years old. Then I thought, "How can I make a deck with the Ace being the lowest card...." If you think about it, I'm adding 3 cards. So, (K, Q, B, C, J, 10, 9, 8, 7, 6, 5, 4, 3, 2, A, J) X 4 suits = 64 cards. You have to ask, "Do I want to play with a deck with 16 cards in a suit with more court cards and some wild card they call the Joker?"