p sure the lives directly taken by capitalist countries total havent really overtaken the 15 million that were executed under stalin
if you bring in other methods of taking lives, maybe, but its harder to argue that capitalism directly leads to those deaths.
You can't step over millions of dead bodies just because they weren't directly executed by a dictator. Hell, even a good portion of Stalin's death count can be attributed to indirect killing, via artificial famine.
Considering the death toll of World War 2, a war started by the Germans for profit and fueled by countries like the United States manufacturing for a profit, even a small fraction of that death toll could blow Stalin out of the water. The sentiment still stands even without that number. The uncountable death toll of labor exploitation is nigh impossible to calculate.