Some jobs that were once done by unskilled workers are now done by who

there are new and trained workers

Explanation:

so first there were no machineries, no studies related to any of the specific work, there was no training but nowadays on the place of the unskilled people are the skilled one who know about all the specific terminologies of the specific work they have to do. They have proper utensils. so that's how the work of those unskilled people are done by the skilled men and women in the new generation