Because actions like pardons cost a finite but uncertain amount of politcal capital. We need to consider not only the benefits of doing so and the options it makes available to us, but also the consequences of doing so and the options it makes available to the enemy. A badly-timed pardon can create momentum for a deep state attack or allow them to pile on more leverage to an existing issue.

On top of that, pulling the trigger on these things generates a burst of positive morale and discussion related to the actions and involvements of the pardoned person. Doing that too early can waste the value of this burst, and basically, right now is when the Assange-related burst is needed most.

Assange -> Wikileaks -> DNC\Podesta\Clinton email leaks -> Wikileaks sources -> Seth Rich -> DC Metro Police \ Peter Newsham -> Clinton

All of this is tied up with the MUH RUSSIA INTERFERENCE narrative of 2016-2018, which is EXTREMELY tied up with the burgeoning CHINA HAS BEEN FUCKING US BLOODY narrative. All the precedents the Dems set back then relating to election interference are now going to be used to fist them with a handful of broken glass.

You are correct that you should trust POTUS and his team. They've been dazzling us for years now with their foresight, planning, and restraint.

Even if someone tries to explain it they don't know the true real reason. Only Trump, his team, and Assange knows

Im assuming he will be next on the list.