Just had a look at XAUBTC, and could only fit 5 years in a chart, and Gold lost nearly 99% against the BTC astronomical rise, if you go 10 years, the lag is nearly 100%.

Now my guess for the real inflation is about 15% per year for the past years, from now more than 20%p.a. Gold did gain nearly 60% in the last 5 years, so you could say it does keep purchasing power against inflation , nearly, but again, it can never be called an investment, a pailful insurance maybe.

Anyhow, it is possible that metals gain some value from here after a decade of total beating, will see, with the looming inflation it is not a bad idea to have some.