look, even when using 8k renders (movie production stuff for when some day a monitor/tv exists) your textures are usually 2048pixel max, some times 4k, but rarely.
Thats because generally items in the scene are displayed much smaller than the full texture resolution.
There is a visualization mode for lightmaps you can use to see what sizes are best.
Obviously it isn’t the same 1:1 for textures, but it gives you an idea of the size needed for decent shadows which are done with a texture.
Also, in the Academy, one of the base series on lighting/materials explains other ways to optimize ans reduce textures so they don’t compromise the memory load.
Another thing is that you should be re-using the same images as much as possible.
You can do a whole room with 1 single texture by slicing the items UVs up to fit in different areas if need be. then the items can all use the same material, reducing the load.
Not ideal to be sure.
the other obvious optimization is that every chair would be an instanced mesh. This applies to anything that can be repeated. Including walls.
Your pics look great. but I bet you that if you duplicate the project and change all the textures to 1080p you would barely notice a diffetence when running them in parallel…