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

https://ellassmartperspectives.urbanvellum.com/posts/is-seven-always-about-luck-or-can-it-mean-something-else

The number 7 is seen as lucky in slots and pop culture because it often represents good fortune. Classic slot reels show 777 as a jackpot symbol, tying to the seven-day week known for new beginnings