What you've failed to note here is that in an automatic you're stuck doing the exact same thing unless you drive it like I do (neutral any time at a dead stop), just with the brake pedal.
Not to mention, the pressure required to keep most newer stuff's clutches released is less than required to hold an auto in place with the brake pedal, or at least equivalent. Add in a feeling of stronger control over how quickly the car is going/accelerating at those low speeds and, well... For the most part I'd take the manual.
I'm not quite sure I get you?
Process for start-stop traffic in a manual, initially moving: Come off gas, press brake, depress clutch as you come to a halt. Either stay in gear with clutch depressed, or knock into neutral if stopped for longer. Then, either slot back into gear, balance clutch/gas and pull away, or balance clutch/gas and pull away. Wash, rinse, repeat.
Process for start-stop traffic in an auto, initially moving: Come off gas, press brake pedal. Stop. Release pressure on brake pedal and creep, or release pressure on brake pedal and press gas. Wash, rinse, repeat.
That's a lot less stuff involved in start-stop traffic, and thats without taking into account faster traffic where you may be going up and down the gears constantly, or very, very slow traffic where in a manual you're constantly clutch in, clutch out, clutch in, clutch out. In very slow traffic in an auto, the brake is literally the only pedal you need to press as creep does the rest.
I'm also not an advocate of keeping the car in gear with the clutch depressed if you're going to be sitting there a while. Increases wear on the clutch release bearings. In heavy traffic that isn't moving every few seconds or creeping along, it's better to slot it into neutral. Saves strain on that leg, too.
Meanwhile, in cases where all traffic comes to an abrupt halt, quickly speeds up to 35ish, then does it all over again... Give me an auto. It's a lot more work in that case to take off, row through a few gears, then stop than it is to just let your foot off the brake, accelerate, stop. Normal suburban driving it doesn't bother me, it's more when everyone tries to run anyone not in their GOTTA GO FASTER TO STOP competition over while getting exactly nowhere.
Ah, that covers part of what I mentioned above 👍