CMS + Webstudio hosted on the same VPS

Yes and no. By using vps you are using a central place. So visitors depending on their location will have a longer latency.

Your site's server will have a fast access to your data - yes. Will it make the overall performance better - not necessarily.

Best performance is achieved by having fast frontend on the edge + fast data access, if not at the edge then at least in the right continent.

If data can be cached for long periods of time then the fact that data is on the wrong continent can be relatively unimportant, because after the first request oyu can cache it for hours or months

So for things like Blogs - where the data origin is doesn't really matter, blog doesn't change frequently.

for things that are updated all the time - fast access to data matters

overall your question can't be answered without knowing exactly what you are building and who is your audience.

thanks @Oleg Isonen , that helps me