This is a common misconception or a poorly phrased statement. It's not true that someone who bought/held tech stocks, or an ETF beat virtually all managed funds or that holding on to ETFs beats virtually every managed fund. It's true that passive investing, in tech or ETFs would have beat the average managed fund, and it's also true that an investor is better off investing in an ETF/diversified portfolio, but there are exceptional managed funds that significantly outperform the market.
The problem is that you are no more likely to know which managed fund will outperform the market than you are to know which stock will outperform the market. Picking a fund that will outperform the market, especially after fees, is just as hard as picking stocks, and in fact it might be even harder due to the fees.
But this does not mean that all, or virtually all funds perform worse than the market or even a segment of it.
One of the advantages of hedge funds in particular is that they can employ leverage in a way that provides almost all of the upside of leverage while protecting an investor from some of the downside. For example if I, as an individual, used leverage to trade on the market and some black swan even happens, not only would I lose the amount I invested, I could also end up in debt and have to sell my house or other assets to cover my obligations.
If I use leverage through a hedge fund, then I still get almost all of the benefits if the market moves in my favor, but if the market moves heavily against me the most I can lose is my investment.