As has been cited numerous times over the years on a.net: what matters the most is a region's GDP/capita, economic activity, and a region's relative wealth and business activity. That drives the demand for flights and airport capacity, expansions, etc, more than outright population.
Austin and Jacksonville are nearly the same size, but AUS sees more than double the amount of passengers as JAX. Nice has a population less than half of Belgrade, but NCE sees more the double the amount of air traffic of BEG thanks the immense wealth and economic activity surrounding Southeast France. Warsaw and Vienna are roughly the same size, but VIE sees about 70% more traffic than WAW.
The difference in pax numbers between VIE and WAW is driven mostly by popularity of low cost carriers in VIE, which is now a bloodbath with capacity dumps by inter alia Ryanair and Wizzair. You will clearly see this by comparing long haul offering which is much bigger in WAW than in VIE. And the latter is mostly because WAW serves a much bigger region than VIE. Also contributing is that Eurostat data show that differences in disposable income and GDP (PPP) per capita are actually not that huge (with WAW having a bit higher GDP (PPP) per capita and VIE having higher disposable income). That would be different if we include a wider region. https://ec.europa.eu/eurostat/databrows ... le?lang=en
Artflyer, I think you've got your statistics mixed up. VIE has much more long haul service than WAW, both in number of flights and available seats. VIE generates greater demand than WAW, period.
I don't want to drive this discussion into OT, but you made me curious, so I looked into actual stats:
Here are the ones for July 2019 (I have no more recent data available):
to/from ORD (so to keep it more within the topic):
VIE: 60 one way flights, 14,901 pax, 747,782 lbs cargo
WAW: 97 one way flights, 24,870 pax, 1,291,610 lbs cargo
to/from entire US:
VIE: 340 one way flights, 73,358 pax, 2,889,361 lbs cargo
WAW: 322 one way flights, 74,315 pax, 3,510,145 lbs cargo
This summer VIE is dropping MIA and starting BOS, while WAW is starting IAD and SFO.
Long haul destinations covered from VIE and not covered from WAW this summer: BOS, YUL, PVG, TPE, BKK
Long haul destinations covered from WAW and not covered from VIE this summer: MIA, SFO, SINhttp://aviationdb.net/aviationdb/F4SDetailQuery#SUBMIT
So, having now included also non-Austrian carriers, to me it is pretty close.