I just want to know. What is wrong with... Ce logiciel n'est utile à rien, supprime-le...?
'ce logiciel n'utilise plus ..... ' marked incorrect?
That’s an active form meaning - This software no longer uses ... You’d need a passive form. Perhaps something like - Ce logiciel n’est plus utilisé... Personally I’d learn the Duolingo sentence using ‘servir à’ as that’s a useful expression to know.
This literally means "the software doesn't use anymore", making the software doing the action.