They do actually. I learned in a marine navigation class that the tides are on a cycle of 18.6 years. If only the moon affected the tides, the cycle would be about 28 days.

https://en.m.wikipedia.org/wiki/Tide > Nineteen years is preferred because the Earth, Moon and Sun's relative positions repeat almost exactly in the Metonic cycle of 19 years, which is long enough to include the 18.613 year lunar nodal tidal constituent.