You should not be thinking that Bitcoin has bright future, i want you to understand and believe that with Bitcoin investments your future is ever brighter and should know that buying Bitcoin aggressively depends on your discretionary income because Bitcoin goes along with the future from 4-10years, then from the discretionary income you can decide to increase or buy Bitcoin weekly or monthly.
If the goal is to buy Bitcoin to be stored for a period of time like you said, of course the person must have a steady income so that he can use a little of his salary to be used for buying Bitcoin every month. And I think it will be a little simpler for those who have a fixed monthly salary, but for those who do not have a fixed income every month it will be a little more difficult to make Bitcoin purchases in a more consistent way. Because most people will definitely prioritize their living needs before investing in anything in their lives.
You don't need to be 100% stable financially for you to be able to invest in Bitcoin, once you have a source of income you are good to go, because it's through their you invest in Bitcoin after you have settled all your basic needs, the reason most investors faces challenge in their investment in Bitcoin is that they try to over due it by investing more than their discretionary income, that's why they mostly find themselves struggling to set and emergency funds aside and even reserve funds, but if you invest only what you can afford, you will hardly struggle with your investment on the long term.
Part of the technical or method that will be used by each investor to invest in Bitcoin is actually up to each of them because it is true as you said that some investors who still experience difficulties are when their desires become greater than the income they have. So they should be able to make adjustments for this in order to avoid difficulties that can arise in their own lives because they force themselves to invest too much, even though if it is done consistently with the measure of their ability, I think there will be no level of difficulty that they will feel later on.