Australia is quite unique in having the option for airlines to cherry-pick from a plethora of GA pilots. Looking at Europe, this isn't the case and for decades, 250 hour HCRPT FO's have been the norm. (The long-haulers may have some SO time.)
Statistics show those airlines are every bit as safe as ours.
I have no doubt a 250 hour FO would create more of a work load for the captain than does a more seasoned pilot, but at the end of the day, statistics don't lie.
It's all a much of muchness in the end.