Why do we even grade people? Just teach the content and be done with it. Sure if a student wants to assess their knowledge to see how well they can answer questions they can do that for kicks. If industry wants well educated people, they should have supervised entrance quizes or exams, the onus is on them. This obsession with catching cheaters is out of control.
If you're asking this seriously:
We need to grade people because that's the best way we have to determine (for one or more subjects) who's:
1. capable enough, so that we can promote them to the next stage;
2. improving or has potential for improvement, so that we can give them the tools or motivation to continue;
3. underperforming, so that we can find out why and help them turn it around (or reduce the pressure);
4. actually learning the content, and if not, why not.
Thankfully, everyone knows this system is flawed, so most don't put too much weight on school grades. But overall, the grades are there to provide both an incentive for teachers and students to do better, and a way to compare performance.
All good points, and I was sort of coming at it from the point of view of catching cheaters. ofc cheaters skew the data but theyre ultimately hurting themselves. They wont pass a companies' entrance tests or will soon find themselves unemployed if they cant do the work. Yes its a problem but I see a lot of effort being spent on trying to detect them. Is that effort proportional to the problem?