I think one depressing example is innovation in weapons and other dangerous fields. "If we don't build it, someone else will first" is unfortunately historically been shown to be true, has it not?
Today's unsavory borderline reactionary doomposting brought to you by: my crippling fear that I'm isolating myself in a political echo-chamber (so naturally I gotta hop online and exclusively ask my fellow leftists)
When did I say it's efficient under capitalism?
(And most liberals aren't capitalists whether you think there's a point to that or not)
Do you have any other examples of existing markets?
I meant capitalist supporters