Ackchyually, TextEdit now has built-in AI as any other native macOS textview control if Apple Intelligence is turned on. It even autocompletes your sentences.
It also likes to save to iCloud by default if you're signed in.
It also likes to save to iCloud by default if you're signed in.
Like any (most) actual native macOS applications.
defaults write -g NSDocumentSaveNewDocumentsToCloud -bool false
defaults write -g NSShowAppCentricOpenPanelInsteadOfUntitledFile -bool false