Those are called Flush valve toilets (compared to flush tank toilets). Flush valves are preferred in commercial buildings mainly because they have a cheaper maintenance cost (less clogs, less stains on the bowl) so building owners don’t need to spend so much on cleaning/plumbing service calls.
Most house owners don’t mind occasional cleaning, and usually their pipes are not sized adequately anyway to use a flush valve.
If you go outside the city you’ll see more flush tanks because more buildings are on well water without a high pressure city water main.
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