Source image: bitcoinmagazine
That's actually NOT right. Gold has also been going up, but a much slower speed, with much lesser volatility if we compare it to Bitcoin. It's currently in its own all time time high right now. For people who don't want the volatility, and merely want a slower surge in price, then Gold might be the more preferable investment.
¯\_(ツ)_/¯
But Gold has taken it more than 20 years for its 10x. Bitcoin can surge to 10x in mere months.
True. Gold has increased.
Regarding the image showing the Bitcoin, Gold and Fiat lines, I also do not fully agree, especially Gold, although on the one hand this flat Gold line can be justified because its rate is different from Bitcoin. This is not much different from what you said that Gold takes decades to reach the increasing line, while Bitcoin can reach a price spike in a short time.
Making both of them quite good investment assets by grouping Gold as a reserve fund.