how to turn off Google's Gemini "AI" assistant on your phone. works on my fairphone5.
you can turn off the shortcut for activating assistant by long pressing the middle button: search for "button" in the settings app)
you can also turn off the shortcut for activating assistant by long pressing the physical on/off button: search for "gestures" (in german it's "gesten und bewegungen", it's in settings under "system"