Buying airline tickets “too far in advance?”

I am planning a trip for my family from Boston, MA to San Jose, Costa Rica in February 2027… so in the next few weeks, I would be able to book my flights… but I’m curious to know if there’s an “ideal” time to do it … my impulsive nature says to book them ASAP, but I’m curious if there’s other times during the year when I could typically get a better deal on flights. An auto-summarized Google search result suggests between 2-8 months in advance, but doesn’t suggest why 9-11 months out would be worse. Any insight / suggestions are appreciated!