I get the power thing...but do you want to be known as the Chief of Staff to a sitting senator that had a massive stroke on camera and died?
Well, those were Democrats, and it didn't bother them too much.
They stayed on as Mrs. Burdick took over for the rest of his term, to help, no doubt.
Now think like a swamp critter for a moment...
Consider, that if the figurehead was
non compos mentis, that means they were running the show for them, and that makes them more valuable/dangerous, depending on how you look at it.
Staffers (who in this case, ran things, and for all I know may be running Turtle's operation there, too) are just one arm of the Deep State but are definitely a tentacle.