Goat lines arrived at the perfect moment: G.O.A.T. means greatest of all time, so calling someone your goat is now a compliment with a built-in joke. That double meaning does the heavy lifting — sports fans, gym crowds and anyone fluent in internet speak will catch it instantly.
The farm-flavoured ones about climbing and stubbornness suit actual goat encounters; the acronym ones work anywhere a scoreboard exists.
The acronym gave goat lines a second career, and the double register is the play: sincere compliment wearing a farm joke, or farm joke wearing a sincere compliment, depending on delivery. Sports bars during any GOAT debate are a ready-made opening.
The literal-goat material — climbing anything, eating everything, fearing nothing — suits hiking crowds and petting-zoo dates. The animal collection holds the rest of the farm, and the sports lines serve the scoreboard side of the metaphor.