TYPO3 v9 has reached its end-of-life September 30th, 2021 and is not maintained by the community anymore. Looking for a stable version? Use the version switch on the top left.
You can order Extended Long Term Support (ELTS) here: TYPO3 ELTS.
Historical Perspective on RTE Transformations¶
The next sections describe in more details the necessity of RTE transformations. The text was written at the birth of transformations and might therefore be somewhat old-fashioned. However it checked out generally OK and may help you to further understand why these issues exist. The argumentation is still valid.