For reference, the Norway Oil Fund [1] holds almost 1% of the world's stock which amounts to somewhere in the neighbourhood of 1 trillion dollars. So the overall size of the investable asset universe for pension funds is really large (real estate, private equity, hedge funds, venture funds, stocks, credit/bonds, etc.) and pretty much all well run pension funds have a diversification mandate so there's no concentration in one asset class.
[1] https://en.wikipedia.org/wiki/Government_Pension_Fund_of_Nor...
But if you're saving for retirement by putting x% of your income into an index fund? That's pretty conventional, most people with retirement savings do something along those lines.
There is little deception. Funds that take crazy risks will say so in their prospectus. There's no chance your S&P500 index fund is taking a huge Bed Bath And Beyond short position when no one is watching.
I can't.
People shouldn't be trusting stocks simply because they are stocks.