As to the wheel gun......ask alf, or Haz,....some folks would rather have the reliability of a platform that has proven itself with minimal mechanical interaction....
Ah, you assume that because I'm fascinated (obsessed) with shooting revolvers that I advocate them for carry.
[Getting on soap box.]
I believe a hammerless, striker-fired, "safety-action" pistol is the most reliable for the FIRST SHOT. Very little of the mechanics are needed for that first shot and with the exception of the trigger, nothing is exposed that can become fouled.
But for FOLLOWUP shots, everything in a semi-auto must operate and it takes up a substantial amount of space for it to occur. The possibility of failure in a less than ideal situation is high.
On a revolver, everything must operate BEFORE the FIRST SHOT can fire, and a large portion of the moving parts (by area) are exposed. However, the space needed for this to operate is the same space that the gun occupies when at rest.
For FOLLOWUP shots on a revolver, if the first one fired, the subsequent ones are very likely to as well. And of course in the case of ammo failure a revolver has a distinct advantage, along with the fact that FTF and FTE are not revolver terms.
There are many other pros and cons between the two platforms but for me (a civilian) FIRST SHOT reliability is the top priority in a concealed carry gun.