I don't think the two are necessarily linked. More infrastructure may mean more money overall, but not more money for the commoners...
19th century commoners, especially factory workers, led more miserable lives than 13th peasants, mostly due to worsening labor conditions and higher population density. Industrialization led to even greater inequalities of wealth than was possible in a mostly rural economy, peaking in Victorian times. And standard of living were at their worst in mid-19th century, despite hugely improved overall GDP.
Did living standards improve during the Industrial Revolution? if you want some illustrations, the height and life expectancy graphs are especially telling...
At prohibitive costs save for the elite. Which may be numerous enough to warrant the extensive lightning rail/aerial shipping, but supported by hordes of laborers nonetheless (especially if you want your Sharn gritty).
I don't entirely agree or disagree, but there are some important points that dramatically modify things. Some f those are on the labor side, others on the creature comforts.
@ChaosOS mentioned labor conditions earlier & he couldn't have been more understated when he simply
said that eberron needs a labor revolution. With regard to treatment of labor, Eberron no doubt has labor conditions in some segments of the economy that make the worst disposable slave labor sweatshops we have ever had look gentle. Worker safety was a huge concern for labor during the industrial revolution, but it would barely register in eberron with the availability of prostetic limbs far beyond even today's
bleeding edge tech& herbal/magical medical treatments that likewise eclipse the kind of trauma recovery that even military medical research has yet to even be at a point where eberron's capabilities are on the horizon A prosthetic limb doesn't need to be the perfect replacement combat usable kind. it can be a much cheaper one that just works well enough to stop the screamer from bleeding & get them back to work. Beatings are/were common & they could be even more severe given magic & magewright healing. The 8hourx5day workweek
(rather than 12 or 16+ hour 6 day) was on of the big wins of the industrial revolution; but toss in something like an enchanted bedroll that lets someone get 8 hours sleep in 4 or less & your looking at an 18-20 hour workday easily. Under those conditions today's
suicide nets seem like positively quaint old news because of course factories install a featherfall wardnet around the building do as not to waste time replacing trained workers who try leaping off, plus that way the old shift can just go up & leap without traffic jams as the new shift makes their way in/up.
On the other side of the coin though, Eberron has (or should have) a lot of things soon if not already available* that were not available until the early/mid 1900s. Magic equivalent indoor plumbing, electric fans, centrail ac/heat not supplied by opening a window or lighting a fire, things we would recognize as modern kitchen appliances, food preserving self prestidigitated ice/cold boxes, etc,,, ot to mention stuff like a stable banking system, affordable theater productions, ample supply of
soap, etc. Yea that day off is going to be few & brutally far apart, but it's going to be a different standard of living than in something like FR or Ravenloft & in a lot of ways even greyhawk.
The lowest tiers of society however are going to make the poorest beggar in waterdeep look like a king in some ways
* Being
available doesn't mean they are cheap, that magehand fan might be a week's pay