I work in "document capture" (OCR, data extraction, and process automation) and every ERP I've had to integrate with has been a terrible experience. I was on a screen share with a consultant for one trying to get my service about the correct permissions and he was scrolling through a list of, what seemed like, two hundred possible roles. Let's not even talk about the atrocity that is their rest API, but at least they have an API as many don't and require RPA (ewww) or similar to input data.
ERP software is painful to use, I 100% agree with you there. But my bigger problem with it is that it encourages a culture of saying things like "streamline knowledge control documentation end-to-end conversion". Fuck that.