The number 7 is seen as lucky in slots and pop culture because it often appears...

https://meaninngs.com/what-does-the-number-7-mean-in-casino-games-and-popular-culture/

The number 7 is seen as lucky in slots and pop culture because it often appears as the winning 777 combo on classic reels. It’s tied to positive ideas like the seven-day week, symbolizing completeness