With regards to the modern game, power hitting is a must, and I completely agree with that. However, in his international career so far, Babar hasn't shown development in his hitting ability, so the real question is whether or not he can actually improve this aspect.
We saw him bat at a higher strike rate this series, but that's because he improved his ability to dispatch mediocre deliveries to the fence. We didn't see explosive batting from Babar in the series.
There is the counterargument, which is also well supported, that Babar alone can't do everything for the team. I suppose it has to do with consistency as well, because if a batsman does not feel as though he can be consistent batting in a certain manner, then it's advisable that they don't. The real question is whether or not Babar has credible evidence that he's not consistent in hitting the ball. If he's never tried it, or never batted outside his comfort zone, then I'm afraid he needs to work on this. If he has tried to, in the nets or in practice games, and if it doesn't work out the way he wants, then I'd say let him bat the way he does.
With that being said, my two cents on the matter are that given Fakhar's inconsistency, Babar's playstyle is perfect for the team because he can step in and provide stability along with Imam. The times where his playstyle is not good for Pakistan's batting is when Fakhar and Imam have already set up the platform, and the need of the hour is acceleration. That's where the argument for his improved strike rate will usually come from. In the first ODI, not many people if any criticized the hundred because Fakhar had been dismissed cheaply. Now when Fakhar and Imam set up the platform, there was due criticism with his inability to accelerate the innings.
When I watch Kohli hit sixes and fours, it's almost always intentional and exquisite, genuinely a treat to watch. If Babar wants to improve his strike rate, he either needs to play fewer dot deliveries or increase the number of boundaries he hits in a game. If it's regarding dot ball percentage, he will need to utilize the crease more in my opinion, and perhaps expose more gaps in the field than he does. If it's more boundaries, a shot I see him play but with not much success is the back-foot pull shot. In modern cricket, that shot is a must, and I usually see Babar failing to connect with or not putting enough power in the shot. He needs to improve his execution of this stroke because it's quite a good shot to dispatch bowlers who tend to use the short ball. Another shot he can possibly develop is an aerial flick to the leg side, to get it over the infield when required.
But one thing everyone needs to understand is that Kohli, when he plays the knocks that he does, it's because he knows there are reliable batsman coming in after him. Babar, with the performances of the middle order, has no trust in the people who come to bat after him, so staying at the crease risk-free is his goal at the moment, and it's not a bad decision in my opinion. We have high expectations from him, but I think we need to understand the pressure he faces coming in at 3, knowing that the batsman below are not capable of even rotating strike much less hitting boundaries.
Those who say that his hitting game holds him back from the best batsmen in the world need to understand that he has a much greater responsibility compared with those, and to perform as he does is nothing short of brilliant. For me, and for many others, he is rightfully one of the best batsmen in the world going around.