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

https://www.red-bookmarks.win/the-number-7-is-seen-as-lucky-because-it-appears-often-in-slot-machines-like

The number 7 is seen as lucky in slots and pop culture because it often represents good fortune and completion. Classic slot machines use the “777” combo as a big win symbol, drawing from the idea of the seven-day week, which feels complete and balanced