>Paying 2x-4x for some piece of land is still waaaaaaaay cheaper for society than drowning in decades-long quagmire while infrastructure falls apart everywhere.

Eminent domain is not only used to acquire owner occupied homes for infrastructure. In some cities it is used to purchase poorly maintained properties from slumlords.

Landlords get what rent they can and don't invest anything in upgrades because they know they can cash out with the city government or public land bank. Promising to pay 2-4x may make the problem worse.

If a building is nearly fully depreciated, and has $0 building value, and the landlord invested closed to $0 in maintaining it, but the land is worth $200K, why should they get 4x whatever they claim the gamed comparables are and $800K from the public for doing nothing?

Maybe 150% of the building replacement cost for owner occupied homes makes sense, but ideally absentee investors holding depreciated properties and vacant lots wouldn't get paid a dime for the land value.