Every word of Torah learned benefits this world in more ways than we all can imagine
I think Feif’s point was that sometimes its detrimental to the communities also. If Kollel is ideal, and 100% of people are in Kollel, AND women staying home is ideal so they stay home, how will anyone feed their children? Forget yeshiva tuition!
Every man is obligated to learn. Working doesnt mean you don’t learn. It just means you fulfill the requirements of your ketubah in addition to learning.