[throw310822]

From a societal point of view yes, it's certainly better to have already built infrastructure that might be used tomorrow than to burn money in capacity that is obsolete before ever becoming useful. From an investor's point of view though, the existence of available, completely unused capacity is disastrous because it means that prices and investments will remain close to zero until all that capacity is used. For the most obvious example: if you're investing in Nvidia, the scenario where data centers remain full of perfectly viable but completely unused GPUs for a decade is much worse than the scenario in which those GPUs were unused but you still have to build a good amount again within a few years. In the first case Nvidia has absolutely nothing to build and your shares go to zero; in the second case the company takes a hit but they keep selling new products.