Their work worth it their pay but it Depend on the idols popularity and schedule.. The top idol like BTS, Twice and BP is really busy during their active time and got some time to rest between other works when promotion over.. The concert and comeback really tiring with the plane goes back and forth..
The busiest idols that noticed are Eunbi and Ive especially Wonyoung , how they are doing tours, comeback and festival with include other variety shows and ads. Noticed that Rei during RM episode sometime look tired and doze off.. The planes they are taking and jetlag suffering really affect the body.
Physical tiredness is better than mental fatigue which will affect your life later