In addition to what you said fiber is an important part of poop. An not just as stuff to push through the tract.
A important function of the liver is body detox. One way the liver does that is to package chemicals so they bind to fiber and get flushed out of the system. Lack of fiber can cause those chemicals to stick around and cause more problems.
It’s a famous quote. The contradiction is intentional. It means democracy has a lot of problems and often looks terrible. However when you step back and consider the alternatives they are worse.