The sig p320 platform is easier to shoot and therefore, better choice for training new shooters. The modular design is also a plus.
However, take everything else aside, such as ergonomics, comfort, grip angle, molecularity, bore height, looks, colour...etc., whatever that floats your boat whether you're Sig fan or Glock fan or some pistol brand fan...
The P320 by design, is LESS safe than the Glock by design. There are already plenty of in-depth comparison and analysis online on the internal safety mechanisms, or if anyone is mechanical inclined, just disassemble and see how each part works for yourself. It's not rocket science.
Now, the possibility that an unintentional discharge happens in real life due to this flaw in design, is likely to be very very minor. But the point is, by design, it might happen.
Both platforms are more than enough for range and competitions. In my opinion, the P320 is actually ahead of Glock in this aspect as there are so many variations of grips and other type of customization directly from factory.
For a range gun, either one would suffice. But if I ever have to pick one that I will count my life on, the 320 would be on the bottom of my list.