1. Lethargy during a sideways market
2. Disregarding your strategy
3. Chasing somebody elses dream
4. Believing somebody elses FUD
5. Using money that you shouldnt be
6. Failing to properly do a self risk analysis before investing
If you can cope with these dangers then this type of investment will do well for you. This is a hands-off, long term method of investing. DYOR, find good coins with bright futures, buy and hold. Dont worry about the daily percentages
Bruh, I wont really say these things you have mentioned are to be considered as dangers of holding cryptocurrency. These things are just natural and can happen to anyone.
If you want to talk about dangers of holding crypto you should go straight and mention the risks involved in holding crypto and the number one risk which people fear about holding a cryptocurrency is that they are very much likely to lose their money due to the market being unstable.