Mmhhh... The translation is pretty bad. Seems like the translator could use a proper editor. For example the correct translation of the title would be: "I went from the strongest job, 'Dragon Knight', to a beginner level job, 'Courier', yet for some reason the Heroes rely on me".
The starkest error is in the last part of the title, the person 'talking' is not relying on the heroes, the heroes are relying on them. 'Hakobiya' usually refers to couriers or smugglers, in the context of the original work 'carrier' can make sense, but otherwise it's clumsy English. I would also consider translating 'shoku' as 'class' rather than 'job' as that's how its usually done in JRPGs.