Some do. Some mean buying something like GLD. That leaves you the risk of the exchange going out of business, though. So some prefer to actually take physical possession of the gold. That leaves you vulnerable to being robbed, though. So some prefer to have it stored in somebody else's vault. That leaves you vulnerable to the vault company going out of business, though.
There is no perfect answer. Different people worry about different secondary risks, and do different things in response.
If you buy physical gold, how does one go about converting that back into liquid cash without getting fleeced? Where do you sell it? I don't get the impression that pawn shops or jewelers pay fair amounts... what am I missing?
Its a hedge against SHTF scenario - full out crisis.
IF we look at history and dozens of cases of runaway inflation or currency crises (germany, argentina, russia default, venezuela etc) where currencies devalued fast in a short period of time - having physical gold (even 5-10% of the total portfolio) would have alleviated the pain.
people lost life savings... and will lose again, as history often rhymes again and again.
There is no perfect answer. Different people worry about different secondary risks, and do different things in response.