Where I live (NC, USA) there was a big issue where commercial property owners have been able to reduce their property tax assessments, not on the basis of 'comparable sales' (like everyone else), but on the basis of the income derived from the property.
I can't say how widespread this practice actually is, but it's not unheard of. Apparently property tax rules are going to vary widely by jurisdiction, which country / which state or province / etc.
There’s one thing you can guarantee in America. If it puts the interests of high income people vs everyday income people, the policies favoring the rich will almost always win out.
It would be absolute stupidity for a property owner to keep a property vacant solely to reduce the property tax assessment. Certainly there are some stupid rich people... but I doubt that the majority are that stupid. There must be some other explanation.
The article writes a bit about property value being based on rents.
So a completely rented building pays the same property tax as an empty building with no renters.