Trigger safety is one factor, yes, but there's more.
All of the internal safeties have a single point of failure - the lug on the striker. If that ever breaks, the (fully cocked) firing pin will fly forward with nothing to stop it. It's an extremely strong part but it's up to you to decide how much you trust Sig to produce millions of these MIM parts without a single manufacturing defect (hint: there are documented cases of them breaking, albeit very, very few, like single-digit few).
Contrast that with, say, a Glock that has redundancies. The firing pin is only half cocked until the trigger is pulled. Even if the lug breaks the firing pin will get stopped by the firing pin block that's located further down the slide (vs back at the lug on the P365). Also, on the Glock the sear has to move in two directions vs one on the P365 - again, it's highly unlikely to drop a gun with enough force to make it go off but at least on the Glock you'd have to drop it in two directions simultaneously.
Bottom line: the P365 is pretty darn safe... but a Glock is safer, as it's physically impossible for it to go off without the trigger being pulled. I can't even conceptualize what would have to go wrong on a Glock in order for it to just go off on its own - seems it would require metal parts to disappear into thin air (if anyone knows of an actual plausible way, please post it). Plus I don't trust Sig in general - their quality control is lacking (to put it mildly); they're still denying that P320s have serious problems. Anyways, I know which one I'd rather have pointed at my twig and berries. YMMV.