The difference being that on Parler the 'cesspool' as you call it is all there is, or at least it is the main attraction.

On Twitter it is easy enough to find, but an average user mostly does have to go looking for it, or at least be following someone who goes looking for it. Twitter also does make efforts to drain the cesspool, although it can certainly be debated whether those efforts are sufficient or even being made in good faith.

You are troubling if you really find that