Completely beside the point. The question was safety, not potential profitability.
Also, please paint the full picture: How many percent of all 1980 investments retain halt their value or more today? My first guess would be: A small minority.
Looking at safety, investing in individual stocks or precious metals like gold is a poor choice. Index funds, or bonds have much less volatility.
To paint a full picture, how many people who invested in physical gold still have it, and how many had it stolen or lost it, or were scammed buying something other than real gold?
Gold does have unique historic status as a currency or a backer of currency. I'm not in 100% agreement, but this does mean some see gold as a hedge against large-scale financial trouble.
However, that same historic status has made this asset in particular vulnerable to investment scams. (https://www.aarp.org/money/scams-fraud/info-2016/gold-coin-i...) This is one caution about this investment that you don't have to worry about as much compared to if you invest in, say, pork futures.
I would argue the "safest investment" is a diversified portfolio, personally.
https://www.macrotrends.net/1333/historical-gold-prices-100-...