The sound advice for the past decades has been, just invest in a low-cost ETF tracking the S&P instead of picking stocks to minimize risk and invest in the market broadly.
So a huge number of people have done that, believing they're diversified, while tech makes up 40% of the index.
Yes you could sell your S&P and find things to invest in least likely to be impacted by a potential bubble, but your average 9-5'er with automated contributions to their 401k is probably not sophisticated enough to do that.
And that's assuming only these companies would be affected if there was a massive draw-down in tech/AI related stocks. We haven't really seen a situation like this before, so it's not easy to predict what effects there might be in the broader economy.
Most people in actual retirement I know do something like keep ~2 years of cash in short-term treasuries and everything else in equities. That gives you a lot of buffer to time-shift equity drawdown, which is the main risk with equities, while retaining almost all of the benefit of equities. Simple and relatively robust.
What you propose takes on a huge amount of inflation risk. How are you hedging that risk? A guaranteed yield doesn't mean you aren't getting poorer. Obsessing over one type of risk and ignoring another isn't rational.
Reducing variance of net worth has a very high cost. Over-indexing on that singular property, particularly when most people can afford some variability, is a recipe for relative impoverishment.
not if you're 80 dude...
Right now it's not clear that is true.
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."
Like my country pension scheme. It went through ups and downs for a hundred years but has always come on top. All you need is a long horizon and a trillion dollars and you basically can't lose.