If you pay close attention then we can conclude that trading is very difficult to maintain consistency in making money consistently and this will make someone feel unsuitable for the job they are doing.
Some people give up because they are unable to keep up and they realize that trading is not for everyone.
Not to mention talking about the age that is getting older so that health can limit them from being involved in it so that what happens is that they will leave trading.

For storage issues you can use a non-custodial wallet and do not need to leave coins on the exchange after trading and this method can be much safer.