Building tons of deca/gigawatt datacenters without a specific monetization plan or need. It still seems like a very temporary bubble most likely to lead to a collapse leaving pollution, waste, land, and community destruction in its wake. If it were to be successful, then ~95% of a previously high-income people (~100M professionals) will be unemployed and/or lose earnings. There is no net positive outcome except for {tr,b}illionaires possibly getting richer.