I guess you have never saved 1/3 your monthly income before. As you said, taking and allocating 1/3 from the monthly income is not difficult, so the only question here is whether you can implement it. Ever since I was a single young graduate, I have managed to save at least 1/3 my monthly income, even after I got married. Just because you can’t save much means other people can’t do that either or logically it is wrong ? Same as keeping fit, that you can’t get disciplined to exercise regularly every day and control the intake of calories does not mean other people can not do the difficult task.
I have a feeling that you did not understand me at all!
I'm talking about the fact that just not everyone can save 1/3, because I assume that a significant part of the world's population does not have income that will allow them to save 1/3 painlessly for life. That's exactly what I meant.
About my approaches to the formation of a financial cushion:
Until 2019 - of the total income, I saved about 25-40% in the form of diversified investments (fiat, crypto, ...)
In 2019-2020, I was saving about 10% -20% per year, because. a significant part of the income went to repair and preparation (appliances / furniture / ...) in a new apartment.
Now there is a war in my country, and for 2 years I have not traveled to other countries, which I used to do several times a year, and now I have temporarily lost another expense item, which allows me to save more.