For me reasons not to invest in crypto are if you don't have any idea what crypto is, lack of ineterest to learn crypto market and investment, impatient these are tje most common reason why you should not invest in crypto as we are know crypto is very high risk and volatility but if you know what you are investing for, the profit here is also greater than investing in any other stock market.
Yes you are right if you dont have an experience or dont know about crypto currency it is very risky thing you will able to loss your money thats why many people saying learn and invest in crypto currency.
Investing here in crypto does not required since investing here is just like putting your money in a bank account and holding it until such time that it has already profit but if you really don't have the knowledge yet with what you are doing and with the one you are investing at then don't try first until such time you are ready.