We've already run the experiment on what an unmoderated discussion forum looks like once it grows beyond a trivial number of users. It's called 4chan, specifically /b/. Twitter/X is just reinforcing the previous findings as it rapidly shifts into being another version of /b/.
The shameless and the trolls push out the sensible people. It quickly devolves into conspiracy theories, grifts, porn, and propaganda.
For some of the channels yes, but /b/ mostly stops at "delete the obvious child porn". Even the more moderated channels take a fairly light touch, only mostly removing off topic threads in addition to the blatantly illegal stuff.
The shameless and the trolls push out the sensible people. It quickly devolves into conspiracy theories, grifts, porn, and propaganda.