You are absolutely correct, it is not impossible for someone to invest in Bitcoin without a source of income I mean what they fuck are they using to accumulate if they don't have source of income.
Having a source of income and having a discretionary income are two different things you need to take not off, they are not the same, what is needed to invest in Bitcoin is a discretionary income not a source of income, because their are so many folks that have a source of income but still can't figure out their discretionary income, so if you have a source of income their no guarantee that such person will invest in Bitcoin and be successful if he can't sorts out his discretionary income from there.
Discretionary income comes from normal sources of income. If there is no income, then there will be no discretionary income. If someone wants to invest in Bitcoin, then the first thing that is most important is to have discretionary income. Now if someone has income but all of that income ends up in running his daily life, then if he saves his required money and invests in Bitcoin, then it will never be good for him. Because investing in Bitcoin is long-term investment. In addition to continuing the investment for a long time, he has to ensure regular discretionary income. And along with this, he will have to form an emergency fund and a reserve fund as a back-up fund so that in case of any unexpected financial problem in the future, he can take money from that fund and solve it without selling Bitcoin. So if someone does not have discretionary income, then he should not hope to invest in Bitcoin. In this situation, he will increase the amount of his income or create another source of income. This will create a position for his investment in Bitcoin when he has stable discretionary fund .