Why go
The city becomes easier when each mode has a job. Walk to understand a neighborhood, use the subway for long cross-city travel, take a bus when the street-level route is useful, and use a ferry when the harbor is part of the destination. Taxis, bicycles, and cars each solve narrower problems. Planning a day around one area reduces unnecessary transfers and makes the scale of the boroughs more manageable.
The full story
New York's street grid makes many short walks direct, especially in Manhattan, but its waterways and borough distances make a single transport choice impractical for every journey. Most days combine modes: a walk to a station, a subway or bus ride across a larger distance, then another walk through the destination neighborhood. The city rewards geographic planning. Midtown, Lower Manhattan, and a single Brooklyn or Queens neighborhood are usually more coherent than a list of landmarks scattered across the map. Ferries add a harbor view, cycling keeps a visitor above ground, and taxis can be useful when luggage, weather, or a direct door-to-door trip matters. Before travel, check the current operator map and service notices, then choose the mode that leaves time to experience the place at the other end.