One of those successful cases of bitcoin hodling was a friend of a friend. They (a couple) took an important risk by investing 60k of a dismissal compensation into bitcoin and making a x100 on it before selling half. I do not know what they did with the rest. Now, these people were not rich, they took an enormous risk compared to their total wealth. They had to really believe on the project and pass though some of bitcoins usual "tests of faith".
For someone with let´s say, a net worth of 1M USD or more plus house, hodling 60k until they became 6M would have been not that much of an stress. Do you think it was easier to benefit economically from bitcoin if you were already a bit up in the ladder?
Being rich generally helps: The investment capital can be large while still remains a small part of their total net worth, so they can achieve big return without worrying about the risk being too high
But after a bull run, their crypto holding has increased 50-100x in value and become the majority of their net worth, they will face the same risk as any other poor people. In such case, only the one with belief would still hold on to crypto and enjoy a much larger return in the next bull run.