Part of King Henry VIII's fight with the Catholic Church was due to the amount of rent-seeking that was going on in England. They were such a ridiculously massive land owner by that point that they threatened the Crown.
Little different- the church doesn’t pay property taxes. Amazon does, unless they have a religious investment arm.
If I had to guess, I’d say land purchases are some sort of vehicle to filter profits for tax purposes. There’s a million rules that benefit property owners for that purpose.
Perhaps they are getting tax abatements by bamboozling the local county officials into thinking that there is going to be some huge local economic benefit from their land purchase.
OTOH when amazon wants to build a warehouse, they probably shop around for municipalities that are willing to waive collecting property taxes for X amount of years to get that development and income tax.
Is it a better buy than somewhere else is the big question though. Sure maybe you'd make your money back in 30 years but that's not what gets investors going. Otherwise everything would be powered with nuclear energy by now.
Detroit going bust is bad if all of your property is in Detroit, but if you have property in 100s or 1000s of cities then the individual booms and busts become less relevant.
Same reason as the Catholic Church. They aren't making more land any time in the foreseeable future.