You don't think that corporate weasels have a way to avoid the tax?
In Nevada, if you have a gaming license you must "use it or lose it", and for this reason, sometimes 24-hour "casinos" pop up in vacant buildings, just to operate the minimum number of hours to keep the license. Like one day a year.
If you tried to implement a vacant property tax they would set up the most pathetic minimum-compliant "business" you could imagine. "Golfball cleaning, $3.00 per ball, open 1-4pm tues-friday".
Eh, just model the law on what shopping malls have in their leases, a "Continuous Operations Clause".
Put into the zoning ordinance business hours where doors have to be open, business has to be staffed and stocked. Property tax penalties apply for daily violations when you don't operate more than the minimum of, say, 250 days per year. Cities could also take inspiration from France in which zoning details and approves the EXACT kind of business, and you could have rules accordingly.
LLM generated lease clause just as an example of the shape of things:
>"Tenant shall continuously conduct its permitted business in the Leased Premises on all regular business days, opening for business no later than 9:00 AM and remaining open until at least 9:00 PM, or during such other hours as are customary for similar businesses in the Shopping Center. Tenant shall continuously maintain a full stock of merchandise and adequate staff to properly serve the public. Should Tenant cease operations without the Landlord's prior written consent, Landlord shall have the right to declare Tenant in default, seek injunctive relief to compel reopening, and recover damages or impose an alternative 'go-dark' rent penalty."