But if the flip side (getting compensated) wasn't also an important concern then maybe far more software would be OSS in recent decades...

>but it feels like if this were an important question it would have halted OSS development decades ago

no because the people who maintain the nuts and bolts of the open source world, like the often individual or handful contributors to projects like ffmpeg or xz-utils have been passionately doing that and at times burning out (which in case of the latter caused pretty prominent problems).

Does the world look to you like it's in a state where important questions and problems don't go unanswered? The reason this stuff works is because there's random guys in a basement in Kentucky somewhere who thanklessly work their asses off and nobody cares. They simply keep doing it because half of the internet would fall apart otherwise.