Torah613Torah
Nobody says be stressed out. The whole concept of stressed out kids is a fairly recent phenomenon and something that needs to be addressed, however the stress may not necessarily be due to the amount of work.
However, it is important that we should urge our kids to be responsible and try their hardest in all things they do. Its just bad chinuch and foolish advice to you tell teenagers that its fine to not try hard in anything.
“OOM: Yes for secular subjects. For Torah subjects, you are growing as a person, so you should study even more than for the tests. For secular studies, you just need it for a parnasa, so no need to obsess about it.”
You make it sound like Parnassah is something that comes easy. I would think that those who did well in highschool because they were diligent have developed an important skill that will enable them to do well in college and at their future job.