There are virtually no "starter jobs" that in the past weren't full fledged "adult" jobs in the past. People have been brainwashed to believe they are lazy if they don't make a living doing a 40 hour a week job instead of demanding a fair living wage.
I think payment should be determined by time and job. I'd say 40 hours isn't necessary for most jobs if you want a decent living, obviously depending on your definition of decent.