I won’t address your comments about the economics of yeshiva students in current day EY.
I do highly doubt your statement that hundreds of thousands of each million frum males in 1700s Eastern Europe were spending sizable portions of the day studying in stiebelach in their stetlach. I would suggest that most of them were toiling most of the day attempting to scratch out a living at their restricted means of employment.
I would challenge you to produce factual evidence to support your claim.