I saw someone playing that way, they could ONLY bulldoze "city services" like roads (so they could replace a road with one with more lanes that fit in the same space, or one with bike/tram lanes) but they could NOT bulldoze zoned properties, and tried their best not to remove even things like police stations, etc.

I think they had a rule saying they could rezone or bulldoze a building that was abandoned; but that of course led to accusations of intentionally forcing buildings to be abandoned (which is a real thing that happens).