Every time someone says “but dark fiber”, someone else has to point out that graphics cards are not infrastructure and depreciate at a much, much higher rate. I guess it’s my turn.

Fiber will remain a valuable asset until/unless some moron snaps it with a backhoe. And it costs almost nothing to operate.

Your data center full of H100s will wear out in 5 years. Any that don’t are still going to require substantial costs to run/may not be cost-competitive with whatever new higher performance card Nvidia releases next year.