Honestly, it depends a lot on the furniture and where it is placed. A typical city bench is usually designed for short rests, quick waits, and heavy public use rather than deep lounging. Many of them have hard surfaces, shallow seats, limited back support, and no armrests, which makes them fine for ten or twenty minutes but not ideal for an afternoon of reading or relaxing.
That said, urban outdoor furniture can be genuinely comfortable for long periods when it is designed with lounging in mind. The best examples have generous seat depth, a relaxed back angle, good lumbar support, armrests, and cushions or breathable mesh that let you shift positions. Shade matters just as much as the seat itself. A comfortable chair in full sun quickly becomes unpleasant, while a shaded spot with a breeze can make even simpler furniture feel much better.
Materials also affect comfort over time. Metal can get hot in summer and cold in winter, stone feels hard, and wood tends to feel more forgiving. Good outdoor cushions need to drain water, dry quickly, and resist mildew, especially in public spaces. If cushions stay damp or collect dirt, they stop being comfortable very fast.
For long lounging, I would look for furniture that supports the body rather than just looks good in a photo. Movable chairs, cushioned benches with backs and arms, shaded seating areas, and mixed seating options in parks or plazas are usually much better than fixed concrete or slatted benches. The key is whether you can change posture, rest your arms, and stay protected from sun or rain.
So, is urban outdoor furniture comfortable for long periods? It can be, but it is not automatic. Standard public seating is often better for short breaks, while well-designed, cushioned, ergonomic, and shaded urban furniture can be quite comfortable for lingering. If you plan to lounge for hours, choose the setting carefully rather than assuming any outdoor seat will do.