Putting builds far away from each other would improve things; however it also has some cons which I will get into after why it is good.
You want to remove as much stuff from memory as possible, as well as reduce the amount of stuff that needs to be rendered.
If you have anchored 100k parts behind you and you are looking forwards at an empty baseplate than you should have significantly better performance than if you were looking at the parts.
Honestly I’m no expert on this area of Roblox at the moment.
If you have builds far away from each other, you will start encountering floating point decimal issues. You should be able to get a good description of that issue by doing a Google search, but essentially it means that numbers like 5.0 and 3.6753 will be defined inaccurately e.g. 4.999999999 or 3.67.
It gets worse the farther you go away from 0,0,0.
It will cause big issues with basically everything, but depending on the size of the game it won’t be important.