If the FO isn’t tipping, I’ll tip for him/her. It’s customary to tip someone who handles your bags, the same way it’s customary to tip a bellman at a hotel for bringing your bags to your room or a valet driver for parking your car.

If you don’t agree with the tipping economy we live with here in the USA then fine, we can have that conversation. Europeans in general don’t tip anywhere near as much as we do here because they’re all paid a much higher wage and the prices reflect that. But whether you agree with tipping or not the fact remains that it’s frowned upon to not tip someone who is working a job where tips are part of their income.