Who isn’t earning less than they were? Teachers are grossly overpaid for their part time gig.
Yet another ignorant remark from you. A teacher's working day does not end at 3 p.m. There are papers to be graded, new lessons to be written, supplies to be purchased, parents of miscreants to be called, mandatory meetings to attend after school, etc. I taught in urban high schools for 25 years and often did not make it to bed before midnight. I was a very dedicated teacher and put everything I could into my lessons and activities. This time after school hours more than balanced out summer vacation. Such intense daily activity with a bunch of kids who do not want to be there requires a recharge of one's batteries. But I still spent a lot of my summer researching material for new lessons in the fall.