Exactly.
I have over 10K hours of ATO time (many here would have a lot more, I'm sure), and I feel very comfortable banging around the place with an F/O fresh from the sim and with precisely no commercial experience. You virtually are single pilot (by virtue of being a trainer).
However, the lesson of training and experience is never more apparent than in the simulator. On occasion, we have had some cocky 25 year old SPIFR guy come into the airline who thinks he knows everything. In the second or third sim detail, we would "fail" the captain with a simulated heart attack and see how he coped. Fine, initially, as he has an autopilot and most modern jet aircraft are pretty easy to fly single pilot.
Now start loading him up with failures. Start with the autopilot, then maybe an engine or a hydraulic system. Not long before our hero is sweating.
To cut a long story short, they all crashed in the sim, and often it didn't take many failures before they lost the plot.
The same held true of ex-military fast jet people, who have a similarly high opinion of themselves and who also proved remarkably fallable in the sim.
Sure, in theory, SPIFR shouldn't be unsafe. But in a world where money is everything, safety is often secondary, and young wannabe airline pilots will do anything to get some multi time, there will continue to be disproportionally more SPIFR accidents.