* Water use: Almost always a red herring or non-issue, unless the DC is being built in an area with water shortages. DC's use a lot of water, but their use is negligible compared to many other industries.
* Neighborhood appearance: They're not particularly pretty to have in your back yard, but much less ugly than, say, a factory. They're not inherently polluting.
* Power draw: This is a legitimate concern as DC's use an enormous amount of electricity. In the short run, it could make sense for deep-pocketed investors to subsidize residential or non-DC power consumption to keep everyone's electric bills from skyrocketing. Longer term, power companies will need to build much more generating infrastructure. I'd love to see a carbon tax to encourage the construction of renewable (or nuclear) power. Sadly, the current US administration seems intent on vice-maxing and ruining as much as they can for future generations.
* AI-driven job displacement: I think this is the real worry people have. The water use thing is an excuse people are looking for to oppose AI.
Usually the financial services company will offer several options: more aggressive/high risk, or less aggressive/lower risk. Most people will just go with whatever is the default option.
So much of the American S&P 500 is dominated by handful of companies that the risk is not that easy to avoid. If or when the AI bubble pops, it's going to take down a lot of the economy with it. You can direct your retirement savings into the lowest yield/lowest risk assets offered by the firm, but you'll forego whatever growth happens in the mean time.
Will the bubble pop next week? Next month? Next year? Who knows. Timing the market is incredibly difficult.
There's a famous quote, attributed (perhaps apocryphally) to John Maynard Keynes: "The market can remain irrational longer than you can remain solvent."