Sure, his lackeys can say he’s in the bathroom or not available when he’s phoning up Nute Gunray in his private chambers. But how does he sneak off to meet Dooku at the end of AOTC? At least when he was out for a stroll with Maul in TPM, it was probably in the dead of night.
The security around Palpatine, (especially after the Grevious kidnapping) is laughable.