Exceptional article Pascal!
I have had the privilege of being in this industry for many years now, and I have found more often than not that design systems create more problems than they are intended to solve.
They become beasts; bloated and overdone, that run amok in organizations and slow down the very processes that they were meant to speed up.
I have overseen the creation of many internal design systems, quite a few of which were living systems, and several of which were fixed systems. The systems, I have found, always need more than they are made of in order to operate effectively.
More than systems are concerned, we need conscious designers. It is not enough that we have designers who can "design," we need designers who can think on their feet and judge a situation, with respect to the system, accordingly.
Many times organizations use design systems as a crutch for "innovation," without engendering real and necessary change.
Why do so many design systems ultimately fail? Simple: design is communication and systems abstract communication for the sake a of speed.
Systemized to every possible degree, at some point, the system will fail, and when that happens it is up to the designers, not the system, to move forward in a way that is reasonable, responsible, and effective.