I still make a bit, but it is far less than I use to make.  I haven't put much effort in this direction in a long time, but I'm curious if anybody here is doing so?

Yes, but for me too it's less than it used to be.

I've never made more than a pittance on advertising

The best hits were a couple of sites I built in a couple of days each that brought in a few thousand dollars over the years, but I never touched them and eventually they got killed by Panda mostly and hardly bring in anything. Haven't even met the min payout for a couple of months now.

I do,  yes.
Still do pretty good numbers (mid $$$$/month)  despite serious neglect. 

No, I don't think so.  Not logged in to check in some time, but I think I'd know if there was anything meaningful going on 

Used to have some seasonal sites that would kick in to action for a few months each year, but not sure they're still online TBH.

The day job (and having a life outside of work) has been the sole focus for a number of years now.

Anette dropped (sold) her sites for that reason. CPM dropped significantly over the years and she couldn't be bothered doing sponsored posts etc.
The new owners are neglecting the sites big time. Think they realized that it was actual work.

Been replacing Adsense with ads sold directly to local companies.
Passive is shrinking. Takes constant energy today.