Actually, a GameObject scale should affect all contents of it without any fancy individual scaling you are reporting. Are you completely sure you have actually moved your objects under the parenting of another entity and scaled that entity? Objects will only scale individually if they are selected individually. In Unity, I…
I don't think I'd recommend scaling everything in your scene. That will have issues with performance - it will have to scale up everything before doing stuff. Non-uniformly scaled items can also cause issues with batching, so be careful there. Really everything should be built to real-world scale otherwise you'll have…