Different transit systems have different user experience, yes.
> would you make the argument that "I need gates so that I don't forget to tap"? Put yourself in my shoes: you would laugh at the idea.
Yes, I'm making that argument. I've lived in places that don't have transit gates for the majority of my life, and I absolutely forgot buying a ticket a few times (since I usually have a monthly pass).
Being reminded about a monthly pass having run out by the gate, automatically charging for a single ride (if I have enough balance) so I can solve the problem later, is great UX.