I think that was nicely conveyed by all the talk of secrecy. Giant fucking eagle attack ain’t exactly subtle.
And there’s certainly reference in both LOTR and The Hobbit to the Eagle’s general disinterest in doing squat till they make their final appearances.
Much of the “but the eagles” chatter resulted from the films where they do pretty much show up whenever its most convenient (as Tolkien feared).
But functionally the reason the Eagles don’t air drop the ring into Sauron’s firey bunghole with it being just as easy a solution as everyone smugly claims?
Cause there wouldn’t be a plot. There wouldn’t be a book. Why didn’t Vader just blow up Leia’s ship instead of trying to board it? Why didn’t Skynet send the Terminator back in time to kill John’s great-grandfather while he was on the toilet, or John send Kyle back to kill the inventor of the microchip? Why didn’t Walt just suck it up and call his former partner for a job with some decent insurance instead of cooking meth?
Cause the most expedient story isn’t in any way the best story, and character is more important than plot.