Who would need to press the power button to actually turn off or restart the device, right?
The setting to change this is also pretty much buried under Settings -> Special Features -> Gestures.
(Yes, I have no idea why the Assistant is in German when the phone is set to English either 🫠)
I don’t use the features you listed that much, so I switched it back to powering off my phone. On my Samsung device, there was a link titled how do I turn off my phone. One of the options suggested was saying, “Bixby, turn off my phone.” Nope.