Is gold really outperforming the S&P 500?

I saw this tweet, which tries to show that gold has been a better investment than stocks:

History: #Gold has beaten the S&P 500 index so far this century: #Markets pic.twitter.com/bDtmmvu4GW

— Physical Gold Fund (@PhysGoldFund) February 14, 2019

I will shamelessly repost the chart it uses to make the case:

That looks very convincing, but there are a few problems with this:
1 – The starting point of year 2000 is quite conveniently chosen. Stocks were at a major peak in early 2000, while gold was at a generational low.
2 – To make a fair comparison we have to include dividends. Here is a good calculator that gives you the total return for S&P 500 with dividends reinvested: https://dqydj.com/sp-500-return-calculator/. From Jan 2000 until Dec 2018 the total return for S&P 500 with dividends reinvested is 157%, more than double the 70% used in the above chart.
3 – If an investor kept all his savings in physical gold, then he would probably have used storage or insurance or both. That would have reduced the given 345% return quite a bit.

Gold would still be the winner over this given period, but not by as much as this chart suggests.

To have a more fair comparison that has both gold and stocks go through a few bull and bear markets it would be better to take 1971 as the starting point. That’s when gold was decoupled from the dollar and started trading freely.
If we use $37.50 as the 1971 starting price and $1283 as the closing price for 2018, then we get 3,321% gain for gold since 1971.
The total return for S&P 500 without considering dividends was 2646% from Jan 1971 until Dec 2018. So, it looks like gold wins.
But with dividends reinvested an S&P 500 portfolio returned 10,813%. That’s how much difference a little bit of compounding can make over a longer time period.
Conclusion: the stock investor is almost 3 times richer than the gold investor over this nearly 50 year period.

Does this mean stocks will again outperform gold in the next 50 years? I don’t know. Some people will probably see this as a reason to believe that the price of gold must multiply by three to catch up with stocks. Who knows?