You are right on the reasons why people switch strategies while investing in Bitcoin but we should not follow up a strategy that we may not be able to maintain instead sticking to a strategy that you find convenient enough for you will be the best choice instead of switching strategies just because of your current status at that particular period of time
However, any strategy can be profitable in Bitcoin investment provided you are doing the right thing at the right time and changing of strategy is more like trading stuff because a trader always rotate on strategy, if a particular strategy doesn't work for them they change immediately just to make sure the market moves in favor of them ( their trade).
Changing of strategies becomes more like trading when you choose to sell within a short period of time otherwise whichever strategy you choose to propagate your investments analysis, it is welcomed provided you are not inconveniencing yourself while trying to adapt to a new strategy.
What determined a convenient strategy is what you have ( your source of income ), if one doesn't have a good source of income whether the person is using the best strategy (DCA) it can never be convenient for the person so a convenient strategy is a function of someone good source of income. For example now, if a business man usually goes to the market with $20 to buy goods or product meanwhile his monthly salary is $100 and then he is been promoted and the salary increase to $200, don't you think the business man will also increase the money he usually use to go buy goods at the market and vice versa but that doesn't mean the $20 is not convenient for him and I don't think investors are tied or band to use a particular strategy for accumulating Bitcoin.
I don't really agree with all you have said about the source of income determining what method should be convenient for an investor. That argument is weak and ignores a lot of variables such as personal preferences and others. As long as an investor have set aside some funds for investment, he has the liberty to chose the DCA method, buying the dips, or lump sum buying. At this point, the source of income is inconsequential. If in the example you gave the businessman's income increase from $20 to $200, he can still use the same funds to for the business but this time the quantity of goods will increase.
Are you among those saying that the DCA method is for low income earners? This statement have been refuted as it has been established that even some instituional investors and governments also use the DCA method to invest in Bitcoin.
You seem to be supporting the notion that