Market forces can't (sustainably) adjust price to less than the cost of production. They can spur process and other improvements to reduce cost but that does take time and isn't always possible, especially in the near-term.
PS. One thing I have always found fascinating - obvious as it might be - is that paper (and paper in large, sufficiently cheap industrial quantities) was a prerequisite for the printing press "revolution" to take place ...
I also would bet a "sacred book" of some sort also worked as a prerequisite, because the demand was huge, making the crude initial implementation profitable. In absence of some sort of sacred book that made the same standard text of interest for almost 100% of the literate population, the second best alternative probably would have too limited runs to make it profitable.
> I also would bet a "sacred book" of some sort also worked as a prerequisite
What you point out is fascinating, and probably right ...
PS. I am wondering if "any sufficiently popular" book might not have done the trick, beyond just "sacred" texts - one of the many knightly tales than making the round, for example.-
Technology trees are definitely a thing. The answer to "Could the Romans have invented an arbitrary fairly modern thing?" is almost always no because they would also have needed a bunch of other resources and inventions that didn't exist yet (and which they might have had little interest in pursuing given that they had plenty of cheap labor, etc.)
Look at electric cars. We've had them longer than ICE cars but they've never really been viable for most cases up until recently. It's not like we just realized we could run a car on electric motors, it's that battery technology has only recently gotten good enough that we can pull a lot of power from them for a long time before they go dead. Improvements in electronics have reduced the size and inefficiency of the components necessary to charge the batteries too. Trying to charge a Tesla off a gigantic linear power supply would be ridiculous.
The people building DIY electric cars in the 90s were using lead acid batteries charged with very slow trickle chargers, not because they were ignorant, they just didn't have access to the better technology we have now. People 50 years with some sort of cold fusion battery from now will look at our crude electric cars running on chemical batteries and laugh.
Paper, interestingly enough, is a good counterexample to this. Paper takes little more than a way to make fine cellulose strands, and a fine-mesh screen, both of which the Romans were more than capable of.
The demand was there as well, Romans imported papyrus from their warmer colonies and went through a lot of it. They also used parchment, but it was expensive, a lot of writing ended up being done on reusable wax tablets.
Paper was invented when the Western Roman Empire was still extant, and while the Chinese could fairly be said to have had a technological edge over the Romans at the time, it's dubious that said edge played a direct role in the invention. It just, didn't happen.
I agree with the general sentiment, and wouldn't call paper "fairly modern" either. But given the topic, it seemed worth a mention.
Some health-related things are an area where important advances could probably have happened earlier in principle: germ theory of disease, importance of sanitation, some relatively simple advances like antibiotics... All seem doable in principle relative to inventing a lot of 19th century industrial revolution devices.
ADDED: The Romans did apparently have some knowledge of antibiotics without presumably understanding the mechanisms or refining them. Per Wikipedia and other sources: "Antibiotics have been used since ancient times. Many civilizations used topical application of moldy bread, with many references to its beneficial effects arising from ancient Egypt, Nubia, China, Serbia, Greece, and Rome."
From the spinning wheel, to plentiful rags, to cotton paper, to the printing press.-
> ADDED: The Romans did apparently have some knowledge of antibiotics
Fascinating. Worth looking into.-
Sometimes, all it took was one person noticing something (midwives who wash their hands post partum tend to have better outcomes, farmers near cows get less sick, or not at all ...)
... but, you raise another good point: First principles, the search for the facts. Benefits at scale come with, consistently, wanting to go from observation, to general principles, to particular application, to mass application ...
... and, maybe, it took rational thought and the scientific method to get there.-
