Photon mapping may be good for pure walls and simple geometry, but if you have something more complex, it fails in most cases.
So i dont know if caching is the best option. What do you think about that?
One of the hardest and challenging scene to render in CGI is Interior as it involve a lot indirect illumination and most interior showcase a large number of diffuse and non highly specular surface ( walls/floor/ceilling/ furniture). So Most interior benefit a lot from Gi caching a reason why corona renderer and VRay are so often used for Interior rendering: https://corona-renderer.com/gallery
Interior rendering isn’t exactly what i will call simple scene ( like product visualisation).
Even the render you posted is an ideal case for GI caching Speed up.So here No way Cycles or Fstorm or any pure brute force engine gonna be faster .
https://www.behance.net/gallery/96502445/Scandinavian-Living-Room
No doubt the glass and the caustics looks great. But in quality of light and shader i dont see a big difference. Something like this cycles render looks great:
https://www.behance.net/gallery/96502445/Scandinavian-Living-Room
And this is a EEVEE interior render :
And another one : https://blenderartists.org/t/eevee-01/1102712/3
So there is almost no need to use Corona or VRay or Cycles or Redshift isn’t it ? Better why not all go for Unreal or Unity ?
And a Old Blender render car vis : https://farm4.static.flickr.com/3448/3206160654_43556a28dc_o.jpg
The point many people here tend to ignore is that Realism is a state not a tool.
You can achieve Realism with a pencil and a paper or even do interior visualisation with Photoshop.
But here what we talk about when speaking about Realism is how easy a given tool help you reach that state. How many tricks constraints do need to overcome before that. What is the minimum artistic skill require by your tools to reach a certain quality.
As you like Devs quote take this one from Stefan Werner : https://mobile.twitter.com/stefan_3d/status/1260146970607398912
As a Cycles developer, I recommend LuxCore if photorealism is your primary goal.