Yes, indeed. The kind of people who call for this as a soundbite have very firm ideas of who should qualify for it - and, if you press them hard enough, they would have to admit that the government 'should' make it compulsory 'for all 18yos who Bert Higgins of Elm Road, Preston reckons could do with it'. Crystal clear.
Even if we discount the army option and go straight to the civilian alternatives, I think the government might have rather forgotten that there is now no goodwill left amongst young adults in that way.
Maybe in the past, when university education was provided free of charge, young adults might have been game to give away their time cheerfully; but now that there is a very costly price on it, that will weigh heavily on the shoulders of those young people until their early old age. The same successive governments that ascribed that hefty value to young adults' time cannot now expect to get it back free.
What a huge insult to force them to pay so much money for their higher education, with such a large penalty for it for most of their working life; yet to quite merrily delay them for a year by dissonantly considering their time so cheap, but just for that one year. The government will support you to do some token helping out, designed to keep ruffians out of trouble and thus applied to ALL young adults; but not to become tomorrow's doctors, nurses, teachers, other key-workers, professionals that make society happen.