Many people are too worried about uncertain income when living independently... while the permanent job that people think about, sometimes is not completely permanent until old age... there are times when companies can suddenly go bankrupt too... so actually, we all don't have a real fixed income... everything has its time, including our heyday...
Nothing is permanent even the public sector jobs can come to an end even before the retirement therefore we should not take everything for grant and think that it would be like this forever while things can really change very fast the same though also motivates people to look forward to new jobs and opportunities, and they don't stick to the one for years.
Relying on trading income alone, is clearly quite worrying if it is not stable.... if you can already make enough money to meet your needs, that is an exception... yes, the point is if someone can guarantee that they can get enough money from trading to live independently with their family... that is enough., the next projection is to find other income so that they can live better.
To be honest, people who say they only rely on trading can be lying because a person who get involves in crypto trading, give a chance to other earning ways to like staking, investing in gems, joining airdrops, and other stuff because trading changes the mind of a person to find more opportunities to make money.