Your side light here is below the ground. Preview doesn't take shadows into account, so the red light is visible in the preview. But in the render, the ground blocks the light so it doesn't do anything. The render isn't unrealistic, the preview is. And if you were setting a stage for a photograph, you wouldn't be placing the light under the floor like that.

Preview is meant to be fast, not accurate. So the lighting model used in preview is really oversimplified. Light data doesn't take into account shadows and spotlights don't accurately portray the cone of light produced by the spotlight settings.

Also, the color of each pixel is not decided by lights. The color is decided entirely by a shader.  (materials) The information coming from the lights is only a hint to the shader about what it should do. The shader can do anything it wants with the light. Shaders can produce bright colors where there is no light, and can produce black even in the presence of a blazing spotlight. While light settings and placement are important, the fact is that you find them unrealistic because your shaders are non-photoreal.

Usually we use shaders that use the light data in smart ways to decide what color each pixel is. Such shaders are called photoreal, because they are meant to be making decisions that mimics real life as seen in photos. Non-photoreal shaders (NPR) do not make the right decisions, but they are usually very fast. 99% of Poser content has stupid NPR shaders on them. And the preview versions of the shaders are entirely NPR.

The shaders that are used in preview are much simplified versions of the shaders used in rendering. Even if all you do is hook up a texture map to the Diffuse_Color and dial in some specular, the preview version of that is grossly oversimplified. Not only are the preview shaders ignoring shadow data, they also do not generate the same answers even if you turned shadows off in render.

Preview shaders also do not generally show anything regarding bump or displacement, and only use low-res versions of the texture maps. And nothing involving raytracing (reflections, refractions) is dealt with in preview.

Photoreal shaders are math-intensive. You don't want them in preview.

If you go beyond a simple color map and simple specular effects, i.e. you use some nodes in your shaders, then the preview has no hope of matching the render in any way.

Your scene looks pretty simple and probably has no nodes in it, but I do see bump and shadows. That alone is going to make it different.

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