That's because you are more interested in getting rid of Sarfraz, than who the captain is subsequently
All of this is true, but you have to establish a precedence as well. When a team is losing and the captain is performing poorly at an individual capacity, there has to be a cut-off point. You cannot tolerate a non-performing captain in a losing team forever, simply because you do not have clear alternatives in sight.
Pakistan literally loses nothing if it sacks Sarfraz as captain today and drops him from the team. We have already reached unchartered levels of mediocrity and lose 90% of our Tests and ODIs against quality teams. This drama of being the best T20I team will blow up as well, and even if is remotely true, Sarfraz is hardly the biggest contributing factor.
I see that his fans nowadays are now using his decent keeping form to take the focus away from his awful batting. Yes it is good to see him improve with the gloves, but batting is an essential component for WK batsmen today and especially when you have a third class batting unit like ours. Moreover, Sarfraz established himself in the team because of his purple patch with the bat, and there is no justification for his poor performances since taking over as captain.
We are a rapidly declining cricket nation and will never be a top team again. As a result, if we keeping asking for "better" alternatives for leadership, we will never been able to find a solution for another 10 years. However, you have to create a winning culture anyway, and you start by ensuring that your captain knows that he has to perform at an individual capacity and be among the best players in the team if he is to enjoy the privilege of being the leader.
If you sack Sarfraz on clear grounds, i.e. because he is not scoring enough runs and the team is losing as well, there is a semblance of hope that the next captain - whoever that is - will be under pressure to perform as a player. Throughout his tenure as captain, Sarfraz has been under no pressure at all to score runs.
Barring the second Test against Australia, he has been a walking wicket for over a year but you would hardly see him comment on his barren run. In fact, even Arthur and our ex-players and experts have hardly sad anything on the fact that he has not been performing. The media has been quiet as well.
Unless Sarfraz starts to score runs, sacking him should be priority number one. Who will be the captain after him to lead this pathetic team to more defeats against the top teams is something that needs to be dealt after. Anyone who is performing individually will be an upgrade.