Slippery slope arguments take into consideration the very human capacity to become accustomed to a certain boundary, and then seek to push beyond that boundary. For good or ill, look at the progression of rights leading to the current transgender/feminist argument over what constitutes a woman. 50 years ago that would not have even been a discussion.

You would be hard-pressed to ever see a government give ground where once they have asserted authority. Only encroaching further into our rights.