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Having both guns, I'm going to say this is not an apt comparison.
If you are talking about IWB or OWB carry with a belt, the P365 carries as easily the S&W 642 - maybe easier. However, that's not the niche the little J frame excels at.
The P365 is 24 ounces loaded, the S&W 642 is only 15 ounces. This is over a half pound more with the pistol, and is significant if you intend to pocket carry, or IWB with sweat pants or athletic shorts without a belt. The latter carry is borderline impossible with the P365 and similar 10+ round pistols due to the weight causing pants/shorts sagging, but not an issue at all with the lighter J frame.
While talking about Appendix IWB, I would not carry a striker fired or SAO pistol in that position that does not incorporate a manual safety. Yes the pistol is safe, but given the peculiarities of holster retention during body movement in that position, the dynamics of drawing and re-holstering from concealment garb, under stress and/or while grappling with an attacker at close range... I only carry DA hammer guns - with a minimum trigger pull weight of 8 lbs and a minimum trigger travel of 1/2" - in that position.
In regards to front pants pocket carry, the angular shape, width and weight of the P365/etc is not nearly as good as the J frame. The loaded weight of the P365, carried in a pocket on daily basis, is too much in my experience for most people. Anything more than 20 ounces causes sagging and an annoying slapping against your leg with every movement.
In regards to jacket/coat pocket carry, the lighter weight of the J frame is still significant, along with the ability to fire while in the pocket. No self-loading pistol can be completely reliable while fired from within the pocket, while the concealed hammer J frame guns will fire the entire cylinder that way if need be. Your hand on the gun, unobtrusively inside a coat pocket, is a significant advantage in cooler weather when the possibility of an immediate threat lurks.
Arguments about the firearm round capacity, or 25-yard accuracy, or reloading speed, are really not the point of this discussion. If you believe you need 10+ rounds on tap, or the ability to reload another 10+ rounds quickly... no revolver will likely ever interest you. (for what's it's worth, back in the day I regularly qualified at 50 and 25 yards on the FBI Revolver Qualification Course with a 2" J frame... just sayin')
On the other hand, as with the OP, if you believe your situation is well-served by the usual risk of 3 rounds in 3 seconds within 3 yards, the "humble J frame" is not only adequate, it is in some ways superior.
I personally pick the weapon suited to the task, and the 2" revolver is often a correct choice. YMMV.