This "Taxibot" seems to be designed mostly on the tarmac where engines are idling to keep the APU happy and reach operational temperature, a place where FOD is

This "Taxibot" seems to be designed mostly on the tarmac where engines are idling to keep the APU happy and reach operational temperature, a place where FOD is often caused by humans, not machines - it's not meant for operations to the runway, where engines usually are at full capacity and humans are absent. Most likely, in this different scenario, there actually is a FOD Advantage.