It is possible to cherry pick any two rounds that have similar ballistic energies and compare them, like this thread. WHY do you want to pit a maxed-out 9mm round against a moderately warm [at best] factory .357mag load?
Do you own both platforms [9mm semi and a .357 revolver]? If so, what are the barrel lengths involved, as the published numbers change with a change in the barrel length.
What is the intended purpose for the round? Home defense? Street daily concealed carry? Open field/farm/yard carry? Backpacking/hiking/camping/hunting/fishing carry? Urban anti-vehicle defense? Zombie Apocolypse?
Yes, both rounds will kill someone dead, if you aim them properly. Yes, both will fail to save your life if you can't hit the threat in the right spot with them.
I have both platforms. If I could only have one platform I'd have different rounds for different purposes. I'd use one type for home defense [fears of overpenetration and hitting my sleeping daughter, for example, as well as deafness], with a second for concealed carry and a third for camping/hiking.
As was mentioned, why are you comparing a maxed out 9mm to a moderately warm .357mag round?
Yes, it is true that a 9mm +P+ round approaches the .357mag round for muzzle energy. Yes, there is a .357Sig round that fills that space between non-+P 9mm and .357mag rounds. Yes, a lot of the .357sig ammo is only as hot as .40S&W ammo. Yes, .357mag rounds start off around where the 9mm +P+ peaks, and goes UP from there. So, there is a spectrum of rounds that have different powers and some overlap.
The sports-car analogy comes to mind. You can have one car that maxes out in MPH at 140mph and another one that maxes out at 200 mph. Which do you want? Do you want to buy the cheaper one that maxes out at 140 mph and keep the engine in the redline until it seizes, as you try to wring 100% of it's capacity out of it each time? Or do you want to run the other sports car at 65% of it's capacity and have it last a LOT longer?
Unless you are trying to decide about whether to buy a 9mm pistol or a .357mag pistol, and you can only own one of them, you haven't given us a reason for any meaningful comparison.
For what it's worth, I wouldn't use anything supersonic inside the home for self-defense: I don't want to be deaf if something else will end the threat also and I don't want overpenetration of my walls to hurt other family members.
I don't have a problem with 9mm +P ammo for personal defense outside the house, but I don't want +P+ ammo out of any gun I intend to keep for decades.
I wouldn't carry a 9mm +P+ camping if I were concerned with 4-legged threats. I'd go with a .357mag revolver. If I were hiking, my first round would be a shotshell for the most likely threats: snakes. Shotshells don't cycle semi-autos well, so this isn't a real 9mm option. If I were hiking the rest of my .357mag rounds would be the 180grain ones that put out over 650 ft/lbs of muzzle energy. Those are more likely to dissuade a mountain lion or small black bear than a 535 ft/lb 9mm +P+ round will.
If I were in Los Angeles and hiking in the hills near/in the city, I'd be more likely to carry a 9mm with ammo I could get back on target with rapidly, as I'd be more concerned with pit bulls, coyotes and 2-legged varmints.
Again, the round depends on the application. You haven't given enough info to really give good insight.
