If such a device was considered advanced or cutting edge or of note back then then wouldn't we expect some reference to the device?
"There are quite a few mentions of devices that sound a bit like the Antikythera mechanism"
https://youtu.be/Iv-zWbxm2lY?t=2695
Jo Marchant is an award-winning science journalist and author of several popular science books including Decoding the Heavens: Solving the mystery of the world’s first computer and the New York Times bestseller Cure: A journey into the science of mind over body (both shortlisted for the Royal Society science books prize). She has a PhD in genetics, and has worked as a senior editor at New Scientist and at Nature.
I don't think there is any record of this device existing other than the device itself, and mention of it after its discovery in the early 1900s.
to some that will be proof that it is not truly an ancient device, and I think that is hogwash. most things just don't last that long, especially paper, which is where mention of the device would be found, if it ever is found.
the math used in the device is not complex, nor is its construction. it is only impressive to us because of what we assume about cultures of that time: that they are dumber than we are, less intelligent.
they were just as smart as us, but they were far fewer in number, and had many more limitations than we have when it comes to the library of technologies and skills they can call on to accomplish their goals.
Could be this mechanism was just an exquisite commission for a wealthy dude to keep on his boat.