The manifesto is a minimal set of principles but every real world Agile shop I’ve interacted with has subscribed to a set of processes that everyone in tech would recognize as “Agile”.
The manifesto has become a safe retreat that agile fans bring out whenever someone has criticisms about real-world agile; Whenever someone has a complaint about Agile as implemented in the real world, someone will show up and try to defend it by pointing out that The Agile Manifesto doesn’t contain the specific thing they dislike.
The Agile industry moved beyond The Agile Manifesto almost as soon as it was popularized. We can’t keep returning to it as some safe home base that shields Agile from any criticism.