Halacha doesnt change if its a diffrent time or place. If it was assur then then its assur now.
Unless I’m wrong, Halacha clearly says that a persons going out to earn a parnassah is not bittul Torah. That being said, if a person will not be able to earn a parnassah without basic knowledge in a certain area, then how is the person supposed to go earn a parnassah? As good as it may seem, its not practical nor realistic for everyone to be a Rav/Rebbe. Where is the rest of the money supposed to come from? Without some people who went to college (of course assur) most Yeshivas would be closed withing a few weeks.