>Airbus reported a commercial aircraft backlog of 9,031

> 10.4 years of production coverage

Kinda true, airlines and manufacturers like to do big order announcements/deals for their future needs of few years all upfront. If Airbus suddenly delivered all 9k aircraft most airlines simply cannot afford it, or take possession and use them even.

For example Indigo is Airbus only operator with a fleet of 450 today and has around 920 more Airbus aircraft (10% of the book) on order. Neither Indigo or Indian aviation sector( of which Indigo is 60%) can triple the capacity today . India need serious upgrades (Terminals, Runways, Gates, new airports) coming online and also demand maturing, i.e. more people can afford to fly for that kind of volume to make sense which even the best scenario will happen over the next decade.

For more mature/slow growing airlines it is function of existing fleet age and the optimal point each aircraft is retired/sold , doing it too early will make them unprofitable .

It is a less a backlog and more their next 10 years of committed sales.

P.S. There is whole other industry aspect around Buy-Sell-and-leaseback financial engineering that can drive order volumes a bit. The backlog/order book also have commodity futures aspects.