Showing the relation between GDP and CO2 is a weird way to establish that countries successfully decarbonized their electricity grid. World in Data provide a better way to visualize this, through CO2 equivalent per kWh, even if unfortunately they don't show the data before 1990.

ourworldindata.org/grapher/carb...

Carbon intensity of electricity generation

Carbon intensity is measured in grams of carbon dioxide-equivalents emitted per kilowatt-hour of electricity generated.

Yes. GDP isn't a very useful indicator of anything much!