For me, GOSH and the courts have been 100% right throughout.
It basically comes down to the reality of "what do the parents really know about medicine?" Nothing is the answer and that, along with their grief is why they have to be removed from a large part of the decision making process. It is telling that Charlie's guardian agreed with GOSH throughout.
In a similar position, it would be very hard for anyone to not grasp at straws. But the hope Charlie's parents had been given by the very mention of the US professor was entirely false from the very beginning. And through their grief, they has lost sight of the truth - there was no helping Charlie. As Becca says, there is no cure or treatment for this disease, a fact which has been lost in the hysteria, making it seem like GOSH and courts were denying treatment on a financial basis. That is just not true.
It seems that the US treatments might
have only slowed or reversed some muscle wastage. It would not have repaired the extensive brain damage, which had meant that Charlie Gard essentially died 6 months ago.
It was best to just let him slip away.