Agreed, and that is aligned with the point I'm making: bottleneck was the production, not consumption. Saying that increased consumption of freed slaves would somehow pull you out of pre-industrial age (the comment I was replying to) is just bonkers.

The increased production was indeed a result of centuries of incremental improvements. You're right to point out that some of them were not about energy, but I would argue that all of the big ones were.

Slaters mill put hydropower to work and even though watermills were medieval, the machines that poured that energy into cotton weren't. Same with the windmills during the Dutch Golden Age which I mentioned above. Increased trade happened through massive wind-powered ships, not slave galleys. (Though the Smith pin factory unlike the Slaters mill is not a real factory but a criticized thought experiment, I wouldn't consider it too influential)

But yes, indeed the steam appeared at the right time, only when there was enough technology to put it to use down the line.