Well the short answer would be to use enough polygons to make an object look like it would in a real world condition as the source asset and use a closed edit environment like Unreal 4 to tailor the output as to practical needs. The needs for for VR are different than the needs for PC desktop use and decisions made based on the sum total of the games design as to the targeted player base is the requirement. In other words if you know it’s excessive then make lit less as limitations as to budget requirements is no longer limited in UE4.
The way to think of it is it’s better to have to much as it’s easier to make it less than trying to take to little and make it do more and in general in “NextGen” game design fidelity of asset is a must for other needs that is not performance related.
The second part of the answer the problem of pushing polygons has been solved with the invention of the GPU that continues to improve as hardware tends to do so it’s no longer the surface count that’s the problem but what you add as say a complex PBR type material with hi K textures that you need to keep an eye on. For that matter there are more than a few assets on Epic’s marketplace that LOD’s the material and not the object.
In general the “edit environment” does what it’s suppose to do of optimizing usable assets with out having to build low fidelity assets based on a number that no longer applies. In this case your 10K vases as a perspective would be like spitting into a swimming pool and saying you made the water rise. 