The reason it's an important distinction is because eg the S&P500 will tend to smash gold over time as a value generative asset (because gold is not a productive, generative asset; gold holds value, the S&P500 generates value (profit/growth/etc)).
perhaps that's an artifact of gold's recent spike in price, but perhaps the SP500 is also in the middle of a giant bubble.
https://www.macrotrends.net/1437/sp500-to-gold-ratio-chart
Go ahead, cherry-pick some other dates to tell the story you want!
The S&P500 return with dividends reinvested since 1971 is $257 for every dollar invested. Gold is $8 for every dollar invested.
And that's with 1971 being the lowest gold price in 100 years and the current price being nearly the highest in 100 years.
For reference, the CPI inflation calculator puts inflation at 7.9x since 1971. So gold track inflation in the best case scenario.
Only one of those investments would also have generated thousands of dollars of income in the meantime.