Is there a reason that AA clicky’s are generally brighter and more common than twisty’s?
Theres a very big assumption in your question and I'm going to assume that you don't have any data to back it up.
Even if it were true that AA clicky lights were generally brighter than AA twisty lights, its very unlikely the switch would be the reason. The emitter, and especially the driver, are much bigger factors in a light's brightness.
Also, a switch actually adds resistance to the circuit. A twisty doesn't have that extra resistance, and all else being equal, it is therefore able to apply more power to the driver. This fact alone likely makes your assumption untrue.
I've measured the resistance in the tailcap/switch assembly of only a few of my lights. So far I have found a low of 6mOhm in a Brass 18650 XP-G2 from FFL and a whopping 243mOhm in a cheap AA clicky from LightsCastle. Most of the ones measure so far fall between 40 and 120mOhms.
I know a few AA twisties use the same (or similar) driver as their AAA twisty counterpart (e.g. ITP-Olight-Maratac). There are relatively few AAA clicky lights compared to twisty; perhaps that explains how AA clickies get more powerful drivers.
Or: clicky AA lights are larger than AA twisties—>small size is less of a priority—>more room for a robust driver with larger components—>able to drive LED harder?
I just realized that the OP didn't say he thought the differences were because of the switch or lack thereof. I jumped to that conclusion on my own.
But are AA clickys indeed generally brighter than AA twistys, for whatever reason?
I think its hard to say one way or the other without having several of each to compare. I only have a small number of each, mostly Fenix and 4Sevens, and I'm underwhelmed by the brightness of any of them, clicky or twisty. They are all in the 100-120 lumen area. I also have a couple very cheap clickys, both AA and AAA, all of which are weaker than the more expensive AA and AAA lights. Based on this I think the determining factor is not clicky/twisty but price. In other words, more bux = more lux.
As for the clickies being “more common” seems like the clicky type is just more popular (at least with me) lol. twisties are a pain in the rear.
There is some reason behind what could be seen as a slight trend. Twisty lights are generally designed as the smallest possible, e.g keychain size, where the extra length added by a clicky would be impractical. In those lights (e.g. Quark Mini AA, iTP A2, Olight I2) max output is generally toned down a little compared to clicky versions which can be slightly larger with a full focus on performance rather than ease of EDC.
Still, there is no inherent reason why a twisty light can’t be as bright as a clicky version.
Yeah, I basically agree.
Clicky will have more mass plus dissipation surface area to hold and could theoretically handle more sustained heat. Users will also find it easier to step down the power, so some might be more likely to do so.
Since I use my twisty lights for shorter use, heat sinking to the body doesn’t really come into play very often. But my guess is a mfgr will play the percentages and tone the heat down.