Many people ignore these rules. Wages are not the only source of income.
The more different types of income (including investment income) a person has, the more stable his financial position.
We have to open up opportunities for other jobs from free time without disturbing the main work, during the technological era we can get other alternative income from crypto investments or study publishers for adsense income or other jobs according to your talent, so one important thing financial advice is to avoid loans and strive for alternative income to be allocated for future savings.