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.
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.
Why other events did not have the same effects are very interesting questions for economic history.
<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"
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.