A few things you might want to consider:
1) your example pays very substantial tax. (property taxes, plus, recently, tax on electricity use)
2) your example primarily used undesirable land.
3) your example grew slowly, allowing the power company to add capacity without a big challenge matching demand.
4) your example is in a heavily connected part of the grid, so it didn't need all of that added power generation to be local.
All of these factors led to datacenters being viewed favorably by Loudon County for most of this century.... but many (and sometimes all) of those factors aren't there for other projects. For example, there are a lot of projects where the datacenter is not paying any property tax or sales/use tax at all.
Heck, even in Loudon County, they're changing regulations to pump the brakes because the hyperscale datacenters are growing electric demand a bit too quickly for them to manage without adding a little friction.
Your anecdote about "it was good in this one county, from 1995 through 2025" cannot be reasonably extended to believe that all of these projects have similar tradeoffs.
(And I'm not even getting into the reality that "this datacenter will let me use AOL" will, of course, be viewed differently than "this datacenter will help my employer remove my job.")
The only reason Loudon county became datacenter alley is due to where the transatlantic cables landed. And Washington DC being next door.
It’s basically the OG networking effect. You put equipment there because everyone else had equipment there.
The rest just grew with it. It had nothing to do with power infrastructure. If anything, datacenters created the power infrastructure in the area.
Agreed on the tax abatement stuff. Those should be outright illegal regardless of industry.