Agile isn’t meant to replace anything. You need to use the right method for your context. No one said the purpose of agile is to replace all other methods.
Agile doesn’t have to be implemented perfectly to work. You seem to be holding agile to some higher standard than anything else.
You have to get over the communism comparisons. They aren’t relevant.
Just because you haven’t worked in an agile environment you enjoyed, that doesn’t mean it can’t work. It can and does work. Just like any other method. And it can and does fail. Just like any other method.
OP didn’t work in agile. They were told that they were working in agile but it was just an excuse for the business to not have requirements and continually change their mind. Every one of the issues they raised could have happened in any other methodology. It’s poor management.