How could one ever prove that? And why should logics dictate its harmfulness? I am missing that logic obviously.

IP protection enforcement shifts the power towards the larger lawyer armies, yes.

However, in terms of spreading ideas and accelerating competitive R&D, patents were clearly beneficial in mutliple cases in my experience. Both as inventor and utlilizing the large corpus of patents to generate new ideas.

And on a longer time horizon the ideas become public good, when the patents expire.