Why is the settings file so large?

[WoodrowShigeru]

My AutoFoldCode.sublime-settings has grown to 6 MB and it slows down saving and closing files.

I've had a look inside and I'm seeing lots of commented-out blocks. For testing, I've opened the first referenced file and cleared any folding. Closing the file did not remove that first file block. When instead I've added a fresh new single small fold to the file and closed it, a new entry was saved into the settings. Reopening the file, clearing the fold and closing it did indeed comment out that new block.

Why does AutoFoldCode.sublime-settings store old information like that?

[Arkane-x6]

Mine was 32 MB
I believe this is due to ST's behavior of settings modifications.
Changes (most) will result to a commented old data, as we can see in User/Preferences.sublime-settings