In fact, done properly, they're not easy at all. Classical philology, stylometric analysis, genuine historical research, or just finding some thing new but interesting and justified about any topic of research in the humanities is hard work.
The problem is that the academic departments have replaced genuine learning with political indoctrination to such an extent that there was probably more genuine research in some humanities fields in the Soviet Union than there currently is in the US.
BTW, the Greeks had a name for the class of persons who were solely concerned with having to work for a living: slaves.
Yes, I am saying cut in half, not abandoning altogether!
There are definitely some things to be done in liberal arts, but, unfortunately, these are not very popular with press. Classical literature, music, linguistic, philosophy, history, religion. That all belongs to the education of the whole person.
And by the way - slaves did not do all physical work. That was a simplification made by Marx. There were always free middle class people, artisans, farmers, fishermen.
An some slaves made it into liberal arts masters (Epictetus).