Cycles losing some realism.

I found interesting post. That is compare the cycles vs octane.

It's not the lighting setup, it's the render engine and the result it provides. Be it using a complex lighting setup, be it using an HDRI env map or even both. Cycles lacks a "little something" and it's not achievable even in post... I'd say maybe it's the path trace code and how it calculates light, but I don't know... the whites are not as white, the blacks are not as black, the occlusion doesn't seem as good, the reflection and refraction of lights doesn't looks as good, it completely lacks caustics... Then you have the filmic color management that is now the default option and is much better than the standard but it still lacks true color, better value range, better lighting, maybe the filmic being a fix is part of the problem to begin with... It's hard to explain, Cycles lacks something that is simply not obtainable using it, and it's the kind of thing that is in other render engines by default... what you can obtain with Octane without much effort is much more than you can obtain with Cycles being an experienced user...

I think so that, too. Cycles providing a toy-like texture. That lack deep tone and atmosphere. I think It's not falls into the category of tone mapping. Thank you.