There are a few types of natural monopolies here. Deregulation only works when the underlying incentives of the market are compatible with the intended goals of the system. It took a strong top-down mandate to get this country wired up [0]. What now seems to be growing is a perverse incentive where utilities would rather sell bulk electricity to industrial customers (easy) rather than the tedious work of maintaining lots of last-mile infrastructure to bespoke customers. But it's exactly those unenumerable small-marginal-use customers where the big distributed-value generation lies!
With a proper mitigation of this perverse incentive, we would see new generation (perhaps even solar and batteries) getting deployed by the builders of the data centers, paying the true cost of their construction rather than externalizing it onto existing grid users.