The two possible ways to likely HODL bitcoin currently, is either you buy it or you earn it.
This is not quite true. Here we can add another way to get bitcoin - to receive it as an inheritance. Bitcoin has already existed for more than fifteen years and at the time of the emergence of this cryptocurrency, people who were carried away by this technology were quite mature (techies) and by now, many already have quite mature children ready to start getting acquainted with this type of assets.
Also, the reason for the emergence of bitcoin inheritances can be illnesses and early death of bitcoiners (many early users left the forum). Remember
Hal Finney and
o_e_l_e_o.
For natural reasons, the number of people who receive bitcoin in this way will increase over time.
We can also consider illegal ways of obtaining bitcoin, such as theft, robbery, fraud, etc. So it turns out that there are slightly more than two ways to get bitcoin that you are talking about.