I don't understand why they're looking to increase the tax rather than just banning them.
This method works better in a free market. Instead of outright banning things, you simply build a system that encourages/disencourages specific things and it basically runs on autopilot.
at some point the additional tax revenue outweighs the downsides
Italian farmers pay effectively 0% taxes on land and the areas are quite poor. Data centers on the other hand pay lots of taxes.
Why would they ban productive uses of land?