Amazon cut a subset of server lives from six years to five, a $677 million hit to nine-month net income. Meta stretched four to 5.5 in the same window — two sophisticated operators reading the same asset's aging in opposite directions, in audited footnotes. Fiber never had this: no obsolescence clock, no margin call on dark cable. GPUs are collateral now, and the depreciation fight hits the cash flow meant to service that debt. The levered periphery could break faster than the carriers did, even though the category is structurally safer.