Just remove Siri from the TouchBar then?
Just curious, what OS version are you using? I'm on Big Sur (but same issue in Catalina). I've got the 2017 MBP 15"
EDIT: I should add, I mean that I could hit the far left blank aria of the touch bar any time in any touchbar mode and it would trigger the esc action. They "fixed" that in an update. I can still press to the left of the esc and trigger esc when the esc button is visible. But often I'll have spotify touch bar "app" open and the esc key won't show, so I have to close the app just to access the esc key, super annoying.