Hi there Nejc!
First of all thank you for your reply and your feedback about the scene, I was losing hope someone would look into my post ahahah
I'll try everything you pointed out, about "dirtying it up" a little bit, especially the antique sideboard and the sofa which I'm really not happy about.
I'll mention something I forgot, which is that the scene is actually a real space, it's my new family house so it all started with trying 3d visualization to check out furniture combinations, colors, volumes etc. It's a real interior project and I used it as an opportunity to try and upgrade my 3d modeling and rendering skills, and I decided to try out Corona.
About kitchen panels: the single lateral ones open with a push and pull mechanism so they don't need handles, i haaaaate them ahahah. I only recently discovered the chamfer modifier, so prior to that I always used the mesh smoothing and I guess that's the strange effect you're describing, I'll correct it.
That being said there are two aspects which I'm actually concerned about: the lacking of "atmosphere" and the rendering time. I attribute the reason for the atmosphere problem to the lighting, but maybe I'm wrong; it's just that the furniture seems to be in a place "without air", as if the light is not passing through the infinite number of particles...I don't know if I'm making sense. It looks like a drawing with realistic ambitions while what I'm aiming for is a photorealistic level. I think it may be because I'm having troubles in regulating the HDRI map, even though I followed to the letter many tutorials I watched on the topic. Or maybe the problem is about how the materials interact with the lighting? I don't know.
About the rendering time, that render picture I attached took about 24h to make it...and since the noise, especially in the corner of the kitchen, wasn't getting better, I stopped it. I know that my scene is very heavy and I probably could do something to optimize it (I'm all ears if you have any tips on it) and maybe my computer doesn't have all the right requirements to make a render in a decent amount of time but for other projects it wasn't such a problem and the results in comparison were more satisfying. So I'm splitted into 1) doubting there's a more hidden problem in some settings that I don't know about or 2) that If I optimize the scene and let it go until almost any noise vanishes and image is clearer THEN I'll have my photorealistic render :\