We all know the phrase 'fly within our limitations'!
Most accidents are caused by pilot error Ie getting into a situation that they cannot handle.
Obviously training and experience play a major parr in how we handle a situation.
There are pilots who make excellent VFR pilots but are uncomfortable in IMC and those who are as comfortable in IMC as they are in VMC.
We know that in instrument training there are naturals who instinctively scan and have a natural ability to handle other areas like aircraft operation, radio operation and navigation while others struggle more.
People can be tested on their reactions , balance. Ability to take in visual information etc and we are not the same.
Put 50 pilots in a sim 50 IR pilots trained to the same level and start loading them with problems.
We all have an overload point but I can assure you that that point will be different in those pilots.
Yes training and experience is vital but they are not the only ingredients in situational awareness.
Ability and makeup also plays a major part they do in being able to drive a formula one car at competitive times.
Pace