Some of us have a job that takes a lot of time and energy that makes it hard to work on Open Source. Having many kids or family members that need help or assistance can take up a lot of your days. Being a family provider, putting food on the table and doing the laundry can take a lot of time.
Having been born in a rich and well functioning part of the world is a luxury and a factor that is hard to change yourself. A privilege no doubt.
In some businesses it is common for employers to ban employees from doing Open Source in their spare time.
We must acknowledge that everyone's ability to spend time and energy on Open Source is unique to each and everyone and the situation may vary greatly from person to person. It can be a decision to not spend more than N hours per week on Open Source, but it can also just be an economic reality that prevents someone else from participating at all.