I was thinking about this recently. If say currency is debased 50% and gold is up 100%, you really are just barely protecting your wealth. Fiat holder is down 50%, but since your 'tax' is calculated based on fiat you're taxed on imaginary earnings. Let's say you bought gold at $1k and now it's at $2k (tracking the 50% drop in fiat money) so you'll pay tax on the $1k imaginary gain. Meaning with a conservative estimate of 30% capital gains tax, you're actually down 15% not taking into account storage costs.
Seems like it really is just something you should buy in a very very small quantity as 'insurance' of some kind, but unfortunately under the fiat regime it cannot really protect your wealth. I guess it really is just 'insurance' in worst-case scenarios and even then there's no guarantee and not something you really want to put much of your wealth in.