Sure, pound locks were an obvious incremental improvement back in the early centuries AD when the Romans built probably the first artificial cuts in the UK.
But it took heavy loads of coal and the economics of canal operating companies halving the coal price in Manchester to convince people it was a good idea to invest in building artificial ditches up hills all over the country to return a profit[1], which of course then opened up scope for new industrial enterprises alongside them. The Romans were perfectly capable of that level of engineering, but they focused on other things, even closer to home.
Agree that "it's all about coal" is too simplistic, but coal was a big deal even before steam mills and trains were commonplace.
[1]not all of them did, obviously. But at least they had limited liability corporations by then...
You coukd say one of the big leaps with canals, beyond the initial ones that expanded/followed existing rivers and remained flat, was the building of aquaducts to take canals across valleys which of course is heavily associated with Romans (though as far as I'm aware that wasn't used for transport of anything but water).
But it took heavy loads of coal and the economics of canal operating companies halving the coal price in Manchester to convince people it was a good idea to invest in building artificial ditches up hills all over the country to return a profit[1], which of course then opened up scope for new industrial enterprises alongside them. The Romans were perfectly capable of that level of engineering, but they focused on other things, even closer to home.
Agree that "it's all about coal" is too simplistic, but coal was a big deal even before steam mills and trains were commonplace.
[1]not all of them did, obviously. But at least they had limited liability corporations by then...