I certainly agree with you that most traders who change their mindset and later focus on investment after series of losses, majorly because they've learnt a bitter lesson
We don't have to learn from our mistakes before we can do the right thing, because we might not like the horrible situation of what may happened on us by then, but instead of learning from their mistakes, they would have better been able to learn the necessary things needed before they fall a victim of learning by mistake, i will also advise that everyone should not be too desperate for investing, instead put all the necessary things in place before starting, this will help to ensure that they don't make mistakes along the line and they have already been well equipped with every necessary information needed for a start.
Many people learn from mistakes. If you trade, if you make a mistake, if you do not learn from that mistake, then you may make the same mistake again and again. I will not give an example of someone else, I will give an example of myself. Before I was not aware of this forum, I was involved in trading. I have made profits many times by trading and many times I have lost all my money. I had no source of income then. After I got acquainted with this forum, I have stopped trading and am moving towards investing. If I find a stable source of income. I will invest using the DCA method.
It's good that you have realize that trading is not best way to approach bitcoin investment rather going for a long term bitcoin investment is the best.
DCA strategy doesn't require having a huge amount or a stable source of income before using it, you already a source of income from your narration which means you can still be accumulating Bitcoin using the DCA strategy from your little discretionary income then on the process you can now make plans on you can increase your source of income and can decide to accumulate aggressively making sure you don't over do it in a way it will affect your accumulation.
Waiting to have a stable source of income before accumulating Bitcoin can lead to procastination of not even starting again, the more you are waiting the more you are missing more buying opportunity, so you can start accumulating Bitcoin with the little you have and increase your purchase amount instead of waiting to have a stable source of income.