Your model of the infrastructure as a perpetually sustaining asset is not correct. These assets must be continually refreshed and improved or their value disappears. The emergence of the data center as a point load has merely coincided with the existing grid infrastructure falling to pieces. The places with the highest marginal energy prices such as California are the places with the fewest data centers. Large consumers invest in transmission assets that benefit everybody.
You would seem to be saying that grid infrastructure needs continual refreshing and improvement to continue carrying the same amount of power? That strikes me as a tall claim, given what I already know about electricity (electronic design and house wiring). I am open to entertaining it, but you've got to provide a reference or at least just describe the mechanism.
This is talking about the capital assets themselves, which are of course separate from regular maintenance like tree trimming.
About the only thing I can think of is something like a bulk of the grid infrastructure was built out 30/40/50/whatever years ago, and is now all reaching its expected lifetime all at once, and perhaps some types of equipment are strictly retired at the end of their lifespan lest they fail catastrophically.