Does dry-brushing really do anything...

...other than create static? Sure, you can sweep up visible debris, but is it the visible debris that creates the ticks and pops? I've given up the carbon fiber brush, and if the records begins to collect more visible debris than I care, I'll drop it back in the Klaudio ultrasonic cleaner.

Has anyone else given up on the dry brush?
I've used Audioquest carbon fiber brushes for many years - - before and after playing each side of an LP.  I've never had a problem, and my records - - many of which are several decades old - - sound great.
I quit using a dry brush quite a while back. I make sure that all records played on the table have had a complete cleaning. Another thing I do, and I believe it's probably a neglected chore for many of us, is to regularly clean the platter mat.

I don't get any accumulation of dust on the stylus, so I assume I'm doing OK.
I’ve pretty much reached the same conclusion- that they don’t do much but push the dust around. The techniques for the Decca/Deema/Audioquest seem to involve pushing the brush sideways or at an angle --one person suggested that contact with the spindle of the record player made a difference- but I find them, and the Hunt EDA (using the scoop technique) largely ineffective (although the latter will give you a nice line of dust). Somebody else suggested that the older brushes were better, so I pulled out an old West German Deema I had, and I do use it occasionally table side. I’ve also tried that "big brush" with grounding wire- meh. I use it to dust the platform on which the table sits, but it doesn’t seem to do much for records. :)
I clean the records really well, using a Monks and a KL, and resleeve- and like the OP, if a record seems to have collected dust after that, i will pop it back into the US for a quickie. I also agree that the brushes can create static. One of the killer brushes was the one with the active polonium element used for brushing photo lenses- man, that thing can carry a charge! (Don’t eat the polonium). I don’t have much of a static problem after cleaning and resleeving so I usually leave the record alone. I also don’t stuff the sleeved record back into the jacket, but into a poly bag that is part of a ’sandwich’ I create with multiple layers--sleeved record in the middle of the sandwich. Less friction, less static.
Remember all the various brushes, the parastat, the dust bug, the original Decca, the original Discwasher? All history.
IMO, it's more of a ritual than a necessity.  I agree that the type of dust it removes does not affect the playability, although I'm sure Doug Deacon would disagree.  Of course it is possible that a piece of crap somehow got onto the record that the brush would catch, so I guess it pays to take the five seconds and just do it. 
Depends on the weather/humidity level.

The Audioquest brush works well during the Summer when the humidity is higher, but during the Winter in the Northeast it creates static on the LP, which then adds the Zerostat to the ritual.
I stopped using a dry brush a few years ago, and instead have been using Last All Purpose Cleaner after each play.  This works well to pick up any dust before putting the LP away into its anti static sleeve.  I dispense the Last cleaner from a small spritzer bottle rather than the dropper bottle it comes in, for better control of the amount of cleaner that goes on the brush.
The old discwasher with a few drops of solution on the edge kept my records clean enough for decades that most still look and sound great.
For me, no dry cleaning process I have ever tried (Audioquest, Hunt) works as well. Ultrasonic wet is the ultimate.
I use a Hunt brush with a spritz of distilled water from a re-purposed eyeglass cleaner spray bottle.  This is the kind of bottle you get at the optometrist and puts out a very fine mist.  Once empty of the eye glass cleaning solution, rinse thoroughly and fill with good quality distilled water.  Hold the bottle 1-2 feet away from the brush and spray in its general direction to very lightly moisten the brush surface.  Helps pick up dust rather than just push it around.  

By the way, ticks and pops are often - though not always - the result of wear from repeated playings eventually exposing voids (tiny unfilled pockets) in the vinyl that were formed at the time of manufacture.    
Yeah, mostly a ritual but it does remove some dust. Could create static sometimes, no doubt. Using LAST after each play may be a good idea but it's too much for me, this and machine cleaning before each play.
Just for a point of clarification, the Last all purpose cleaner was designed as a maintenance cleaner for records that have previously been thoroughly cleaned.  As such it takes no more time to use than a carbon fibre brush.
The ones with a double row of short grounded conductive carbon fiber brushes work well IMO.

The original Decca and Sleeve City brushes are the ones I use.

The brushes on the Audioquest are too long.

The brush must be used properly. Lay the brush on the record at a slight vertical angle, and slowly tilt the brush in the opposite direction of record rotation, then lift off. Hold down the brush gently! Do not slide the brush as the collected dust will be dragged into the grooves! Then turn the brush in the holder to knock off the collected dust. You can see the collected dust on the brush as evidence of effectiveness.

I use two carbon fiber brushes; first brush is rolled quickly for one revolution of the LP to pick up the majority of any loose dust. The second brush is rolled slowly for a couple of revolutions of the LP. Then I swipe the brushes against each other several times to clear off the dust. Finally, I take one of the brushes and roll it for one revolution and then quickly sweep the brush off the LP at an angle. That takes care of any larger particles that weren't picked up by the first two passes.

After each play, I use one brush for a quick touch up and clean it off using the other brush.

I removed the handles from my brushes and grip the brush directly, which seems to help with static problems. I store both brushes in a small wooden box to keep them from collecting dust.

Are the brushes effective? Not for cleaning; that requires a vacuum RCM of some sort. But to sweep off surface dust I think they're better than nothing.