using backspace is impossible because it will just delete characters far from the actual cursor position

Example. Here is a note on wisp vs primal: https://blossom.primal.net/1f1d5a7d286bc430983b7db56b9f1ffb6f0c7f899742fd32c18fbed6bad629c2.jpg https://blossom.primal.net/c38f8612a74e869b6bf0032648b884a40a20b7cada6bd28290c0b68ea7d75384.mp4