It is interesting that they appear to have solved or at least dramatically reduced the porn spam. Still cant open a post though without seeing 10+ posts about something completely unrelated in the comments

No, they haven't. I have at least one porn bot start following me every day. In any thread, a porn post can just randomly appear. TBH, the rate at which it's getting worse is increasing.

I'm mostly reading political tweets, and for the last year or so I have never noticed that - the comments can be of very varying quality, as always on an unmoderated forum, but I don't remember too much offtopic. Maybe it depends on who do you follow and who the bots are targeting - except Musk, my follows are usually not celebrities, so maybe bots don't bother targeting them.

I don't recall ever seeing porn spam in my ~8 years of using the site pre-Musk. Probably a few incidents here and there, but nothing notable enough that I remember it happening.

If the skeleton crew has finally managed to fix it more than a year after causing it, I guess that counts for something.

I don't think porn spam reduced at all, but indeed “engagement spam” has skyrocketed which makes porn spam less visible on popular tweets (but it's still prevalent everywhere else). And there's also much more sex workers than ever before advertising their onlyfan…