About the same.

AIUI, they see a few benefits:

- it will ensure someone holding onto empty land for future use will have to pay at the same "rate" as you do. They don't get a discount simply because they choose not to use the land. If you aim to collect the same total amount of revenue, this would lower your tax.

- Use of land would be better optimized if there was no disincentive to build an expensive (eg bigger/denser) building. IMO this is flawed in that local land use rules are the bigger issue compared to tax policy.