The risk was very high and it looked likely that Bitcoin will fail soon.
Those who were really lucky were those paid in bitcoins or mined bitcoins very early on then forgot about their bitcoins
Or those who understood the technology behind it, believed that there are no other serious options to replace it, and thought there was very little chance that it will fail, and a bug chance that it will take off and replace much of the financial system. There are quite a few of us who thought the concept of "cashing out" of bitcoin made as much sense as "cashing out" of dollars.
By the way, how many people have 100% of their savings invested in dollars, or euros?