If plugins are bypassed, why do the GUIs still show signal?

I can HEAR that the plugins are actually bypassed when I engage the bypass, but why do the various plugin GUIs still show signal - as if they are still processing signal? Doesn’t this waste CPU?

On the contrary, this is exactly the idea of Bypassing in the Master Section: processing still happens, so that if you un-bypass, you can hear the sound with no latency and crack at transition.
If you want to put the plugin completely Off, you can Control + click on the slot.

Hm, OK, this explains the behavior. Thanks, Philippe!