Star Wars: The Acolyte official trailer

[Errorname]

"lolz just kill the leader" is not the grand plan that solves everything that it might at first seem. And even if actually feasible, assassination is probably not something the Jedi would be cool with.

The Jedi literally do send somebody to kill Grievous (not really a proper assassination, Obi-Wan brings an entire army with him, but still), and sending Anakin on that mission at least keeps him off coruscant and away from palpatine for a bit, buys them some time.