Man how would you say discretionary income is more important than reliable income source? Like, what actually gives birth to discretionary income in the first place? is it not the income source? If you don’t have a stable way money is coming in, how would you now have anything left to invest? That source is still the foundation at the end of the day.
And again, I get what you are trying to say about people with unstable income still managing to invest a bit from what is left, but honestly that's not sustainable. It is not even advisable in most cases. Someone with no steady income should focus first on sorting that out, get a job or a side hustle that can at least cover basic needs consistently before talking about discretionary anything. Otherwise it is easy to end up stuck or even worse, frustrated.
It is not mandatory to have a steady income or a job before having a discretionary income to invest in Bitcoin, for example, a student in college that does not have a job or side hustle, that is focused in his/her academic, he gets his weekly or monthly stipends from his parents or friends and well wishers for a well serious and focused student that is not willing to rely on the parents after he must have graduate, while in school from his stipends can decide to start investing right from the day he entered school or along his academic journey of 4-5 years would have invested reasonable amount of his stipends that has served as his discretionary income using the DCA strategy to accumulate regularly and at his final level or when already graduated must have accumulated reasonable amount of satsh in his portfolio, instead of lavishing those extra money on unnecessary expenses or buying double the items he had already.
At his graduation, he would have gotten reasonable amount of fund to startup his life without depending on his parent for survival again.
There are also some persons that does not have a steady income or even job yet are being paid stipends for their upkeep from their rich family and don't see any need of getting a job, such money can be used from the there to start investing in Bitcoin.
Bro I think you’re kinda missing what I’m saying here. First off, what is the actual meaning of steady income? Let us not complicate it. If someone, like that student you mentioned, is getting regular stipends from their parents or whoever, whether weekly or monthly, that right there is a form of steady income. It might not be from a job or business, but it is still consistent, predictable money coming in. That is what I was referring to.
So when I said it is not advisable to invest without steady income, I did not mean everyone need a 9-5 job (and yes if you are not receiving monthly or weekly stipends, then you should go get a job, or have a skill you can monetize) I just meant there should be some kind of reliable inflow that covers your needs first. From there, what is left can become discretionary income, which is exactly what that student is using to DCA into Bitcoin like you mentioned. So yeah, we are honestly saying the same thing, just wording it differently.
Here is google definition of steady income and also a definition in the context of student stipends:

Are you now saying that persons like this can't invest in Bitcoin.
And of course I’m not saying those kind of people can’t invest. They definitely can, as long as they’ve sorted their basics and they’re not putting themselves in a tight spot that would make them go back to their bitcoin investment, then they can 100% buy Bitcoin. Let’s just not mix things up. The main thing is still having something stable coming in regularly, no matter the source. That is all I was trying to point out. Thanks for your opinion though…