高卒26歳女だけど、英語を教えて稼ぎたい！英検とかTOEICみたいな資格取るよりも、まずは大学行った方がいいよね？

The same thing is true of the low-educated people. It is because they didn't study much even though told to study hard by their parents and teachers that they are low-educated. That is, they are just lazy.
It is difficult to believe that those who were lazy when in school suddenly become diligent after they enter the office. It is not because they are intelligent but because they are quite likely to follow earnestly what the company orders that most of the companies prefer highly-educated men to the low-educated.