Black Plague ended in 14th century while industrial revolution started in the 18th. There is no connection.
One of the many, many descriptions of this is here (many because this is the mainstream theory): https://cepr.org/voxeu/columns/black-death-and-industrialisa...
The first technology wasn't the steam engine, it was eating beef instead of just grain, and having cattle pull plows. We don't think of that as a huge technological revolution, but it was a dramatic efficiency gain at the time. It wasn't a new invention, but there wasn't enough surplus to deploy it widely before that.
Yes, there were multiple further steps that needed to happen, as you note. But the black plague got the population "unstuck" from a local minimum that they could not grow from, to being able to have cattle plow the fields and eat meat that allowed them to have some surplus to capture the further gains.
It's not that the later gains were inevitable, but that they never would have otherwise happened, and the growth rate started with the plague.
It's like saying the current AI boom started recently, there's no way the steam engine was related. It is a clear causal chain, even though many things had to happen in between.
But before the black plague, at least the "western world" was stuck in Malthusian dynamics where there was no growth in technology or income.
Yes, at each step keeping the 3% growth needed things to keep going, but the big thing was unleashing the nonzero growth rate, to get unstuck from the local minimum.
This is history not science so it is super incomplete.
We definitely know that the trajectory of the industrial revolution was kicked off at the plague.
We don't fully understand why there major growth periods at other times that quickly fizzled out, and what is different.
What separates those periods from the plague to the industrial revolution is a super interesting question for economic theory.
Yet, the causal chain is clear that the plague kicked off a period where investment and compound interest began to pay off, that continues to today.
However, economic growth was basically flat before the Black Plague, and increases were basically random events that went back to Malthusian dynamics.
Only since the Black Plague has the world enjoyed exponential economic growth.
Most people talk about the industrial revolution, a lot of other comments talk about the british agricultural revolution before that, but economic historians have identified the inflection point at the black plague - that's where compound interest really started to be a driver of growth, it barely existed before that, at least on long time scales.
<quote> One cannot, of course, “know” this in the same way that one can know the date of the battle of Poitiers; applying economic analysis to the spotty record of commerce during late antiquity is a tricky business. However, as can be seen in a subtly reasoned 2003 paper by two development economists, Ronald Findlay of Columbia and Mats Lundahl of the University of Stockholm, it is compelling, as well, despite its reliance on a number of simplifications. </quote>
This would be like saying "well drunk driving doesn't cause accidents because I drive drunk once and didn't get in a crash"
Why other events did not have the same effects are very interesting questions for economic history.
The elites being able to capture some of it was what allowed for science and the enlightenment to happen, which eventually led to the technology that inspired the industrial revolution.
The big picture was it was the beginning of compound interest. This was a many step process over hundreds of years.
Basically, one common version is 'pro-elite' and blames the stagnation prior to this period on 'Malthusian dynamics' (over population beyond the productivity of the land). Another version is 'anti-elite' and blames the stagnation on the capture of all surplus by the landowning elite (who are not motivated to invest it other than the bare necessity to maintain status quo).
While there is considerable room for nuance and disagreement, Malthus is considered largely discredited by modern economics. As the population increased, so did the productivity of the land. Regardless, the fact people lived bare subsistence lives under feudalism does not imply the max population had been reached - they are still paying excess as rent. Peasants paid 1/2 their crop in rent, consumed 1/4 and replanted a 1/4 (crude approximation). This is very similar btw to modern US - there are 100M renters and the median rental household pays 50% of gross income to rent + tax.
Compound interest and capital investments predate the medieval period by thousands of years. There are cuneiform tablets documenting these kinds of financial arrangements.
'AFAIK the leading theory is that without the massive shock from population decline due to the bubonic plague, that surplus would have never existed to begin with, so how it was allocated would have been moot.' This is highly dubious/contentious.
https://www.cambridge.org/core/journals/journal-of-demograph...