@Natasha_Jay I think that most tech companies (or companies of any kind) are simply bad at hiring.
Specifically, the usual strategy is to gather as many applicants as possible and then reject them for arbitrary, often spurious reasons until the workload shrinks to a tractable size.
They can get away with it for two reasons: Permanent cyclical unemployment means that there will be a superabundance of qualified applicants; and the companies take steps to protect themselves from their employees.