So why don't they apply for other jobs? Also, there seems to be a market rate for developers, which is usually not a bad salary. What is the reasoning for assu

So why don't they apply for other jobs? Also, there seems to be a market rate for developers, which is usually not a bad salary. What is the reasoning for assuming most of them are underpaid? Because a lot are 10 times developers? Is it about information asymmetry, or worse, complete unknowns because even the developers themselves don't know how good they are? Would helping developers discover how good they are help their cause? Do sites like HackerRank help, or are the problem sets not relevant enough to the real world?