A lot of reasons, learn and never invest in altcoin and abandon it and say you will come back in the future to cash out millions, you might just return in the future and discover there is no longer a project associated with the altcoin you bought.
If you must be Away for even a day in this space, Buy Bitcoin instead.
And never keep your assets on any exchange until you make sure they are in a wallet that you have complete control over.
Your advice is right, but many of the beginners may not realize that they should not keep assets on the exchange. FTX is now a good example for everyone to believe that the exchange is a place to trade not long term storage. Invest in bitcoin, and hold it in a non-custodial wallet, that is good advice.