Sublime with no windows open: 410mb of memory
CotEditor with no windows open: 80mb of memory
BBEdit with no windows open: 85mb of memory
In the Activity Monitor.
CotEditor with no windows open: 80mb of memory
BBEdit with no windows open: 85mb of memory
In the Activity Monitor.
Of course, there are a million different workflows people use, not to mention different plug-ins and language packages, etc., so it may just not work for you.
But I don't think there's really an inherent problem.
I'm not sure if you are familiar with how virtual memory works but if you are, then I don't understand what's your point.