He surely lacks some skills in bunch riding, but I don't think it's that bad. Last year at Dauphine was mechanical that caused his crash (he was catapulted over front wheel). This year Paris-Nice was his fault yea but that happens to everyone (plus this was first race on a new bike and disc brakes, might be a factor). In Tour this year, first crash nothing could have been done, second was weird one and is still unknown what happend (here I would say his mistake was riding alone and moving up).He was fine at the Tour last year. Didn't look like the crash affected him.
I think racing in junior ranks means considerably when it comes to instinct.
Implicitly teaches riders and develops sense.
All in all, could be worse