I will say crypto isn't a safe Haven and there is no 100% guarantee in crypto investment although one can attest to the fact crypto isn't ponzi but yet it's not just an easy adventure its an ever learning business option that could be passively yielding and at the same time bankrupt yielding depending on ones approach.
If crypto was that easy to go by we would have had more than half of the world's population living very comfortably not giving much concern to their economic data any longer. But the truth remains crypto investment is more difficult compared to manual businesses
You are right that there is no guarantee in crpyto currencies, but the same goes for businesses. Having your own business doesn't mean you are rich, it can be a big problem if it's failing and you are going into debt trying to save it. I think that almost all business owners can tell you they need to work harder than the average employee, need to invest more time, energy and nerves to keep it running. With crypto currencies we don't have such big problems. For me crypto coins, as almost any other thing in life, requires work to be successful. With out real effort is not going to work. Like you said, just buying a few coins and thinking we will become rich overnight is wrong and not realistic. In trading and investing we need to manage our expectations and not focus on greed.