It hasn’t kept up with inflation and the price of hard metal commodities so it’s more like the price keeps going down:

https://www.macrotrends.net/1369/crude-oil-price-history-cha...

https://www.macrotrends.net/1380/gold-to-oil-ratio-historica...

Given the sharp rise in production since 2010, it seems the flat price has more to do with increasing supply and less to do with waning demand:

https://www.eia.gov/dnav/pet/hist/leafhandler.ashx?n=pet&s=m...

https://ourworldindata.org/grapher/oil-production-by-country