Completely agree, it would be very helpful to get even just a breakdown of what the ram is being used for. It's unfortunately a lot of work to instrument.

> sublime consumes 200mb. I have 4 text files open. What is it doing?

To add to what others have said: Depending on the platform a good amount will be the system itself, various buffers and caches. If you have a folder open in the side bar, Sublime Text will track and index all the files in there. There's also no limit to undo history that is kept in RAM.

There's also the possibility that that 200MB includes the subprocesses, meaning the two python plugin hosts and any processes your plugins spawn - which can include heavy LSP servers.