The transfer will happen sooner or later, because from the information gathered he has already reached an agreement with PSG and his salary will be 4 or 5 times his current salary at Napoli. PSG is not a team that can polish any player, they always buy ready made players for exorbitant fees, PSG and Manchester City are the reason why transfer market of today is like this, buying players with big money. Besides PSG didn't sell Mbappe for a penny, he Mbappe was a free agent and Real Madrid got him for free.
That is a very natural thing and I think it is not a complicated problem as long as teams like PSG and Manchester City can afford it, because a team must have a higher financial level in order to recruit ready-to-use players and can improve the quality of their game in every match. And for now PSG does need to target players with that model because PSG still often fails when competing in the UCL so it is quite natural for PSG to buy players who no longer need to be polished perfectly for such a long time.