The cost of laying wire is virtually the same as laying fiber, so the difference really comes down to the material costs. The only good reason to use wire would be existing installations, as you sidestep that cost entirely.

But perhaps the wire is already there. I don't think anybody advocates for building entirely new datalinks using this. Laying another 1km of cable is much more expensive than 2x200 USD to reuse existing cable.

Whatever EUROCARE said about existing installations applies.

Though what I had in mind was that when I was handling optical fibre as a layman (we have fibre to the living room here in Singapore), that fibre is a lot more delicate, so would require a bit more care to handle than copper. But I guess that's probably not a major cost factor, if eg you have to dig a trench for your cable.