Honestly, the answer is not a simple yes or no. Curved park benches can feel more comfortable for many people, especially if you stay in one position for a while, because the contour follows the natural shape of your thighs and rear. Flat benches, on the other hand, give you more freedom to shift around, sit cross-legged, stretch out, or even lie down.
The real difference comes down to how the curve is shaped. A gentle, shallow curve with a smooth dip under your thighs can reduce pressure points and stop you from sliding forward. That is the ergonomic side of a well-designed curved bench. If the curve is too deep or the slats are placed at strange angles, it can feel like you are locked in one spot, and after twenty minutes your lower back may start complaining.
Flat benches are not automatically worse. A flat bench with wide, smooth wooden slats can be very comfortable because it lets your body choose its own posture. The problem is that many flat benches use narrow slats, hard edges, or slippery paint, which can dig into your legs or make you feel like you are perching rather than sitting.
Material matters just as much as shape. A curved concrete bench in full sun can feel hot and rigid even if the contour looks inviting. A flat wooden bench in the shade often feels nicer simply because wood does not absorb or release heat as harshly. So outdoor bench comfort is not only about the curve; it is about slat width, finish, slope, and where the bench is placed.
From my own experience, a well-contoured bench with wide slats and a slight backward slope is the most comfortable for reading or people-watching. It kind of hugs you without forcing your knees into a fixed angle. But if I want to turn sideways, talk to someone, or sit with one leg up, I would rather have a flat bench. So curved seats are not universally better; they are better for one main sitting position, while flat benches are more flexible.
If you are choosing a bench for a park, courtyard, or garden, think about how people will actually use it. For short rest stops along a walking path, either shape can work as long as the surface is smooth and does not hold water. For places where people linger, a gentle curve with broad supports can feel more inviting. But avoid deep curves that create a bucket effect, because tall, short, or larger users may find them awkward.
In short: yes, curved seats can feel more comfortable, often noticeably so, when the curve is shallow and well built. But a good flat bench beats a badly designed curved bench any day. The comfort is in the details, not just the side profile.