Trying to point out single factor is a exercise in stupidity.
Time matters, places matter, culture matters, food, existing technology, technological connections with other regions, math, scientific progress, etc etc.
For example you need to be able to make blueprints. To make blueprints you need the math technology, the printing technology, and drafting technology, and the language necessary to all be developed first.
There are hundreds of thousands of different variables. Probably millions. More probably trillions.
None of them aligned for the Romans. All of them aligned for coal mining industry in Britain.
Time matters, places matter, culture matters, food, existing technology, technological connections with other regions, math, scientific progress, etc etc.
For example you need to be able to make blueprints. To make blueprints you need the math technology, the printing technology, and drafting technology, and the language necessary to all be developed first.
There are hundreds of thousands of different variables. Probably millions. More probably trillions.
None of them aligned for the Romans. All of them aligned for coal mining industry in Britain.