If an investor is strictly investing in bitcoin with his discretionary income, he is free to invest in bitcoin with all his discretionary income if he chooses to do that, and he will not have any problem in solving his living expenses because discretionary income is meant to be used and paid for non-important items like vacation. Any financial crisis that happens after you have paid for your monthly expenses should be treated as an emergency because you don't plan for it, and you can freely depend on your emergency fund to solve the financial crisis and keep investing in bitcoin consistently.
Anyone is free to do whatever they want with their cash but let's be honest, you can't be buying aggressively all the time it's not possible cause at some points you'll apportion your discretionary funds into other areas and slow down for a while, which makes lots of sense. I know it's the sacrifice investors who recently started are giving to build a better portfolio but then you can't sacrifice forever since you'll still need to go on vacations, entertain yourself and so forth one can only be aggressive for a few period of time, slow down then continue again after a while but saying that you can be aggressive althrough the year, for someone who recently started investing, I wonder the magic you want to perform, remember you're a human and having fun is part of our nature too.
I quite disagree that it's not a problem if you use all your discretionary funds to be accumulating Bitcoin because life happens and problems can unexpectedly arise. Ofcourse it's your money and you have a right to spend it anyhow you like but using all your discretionary funds to buy Bitcoin is not a good financial plan.
Inorder not to make financial mistakes from your total income you should first remove your basic or unavoidable expenses then the rest goes into your discretionary funds. You need to have a special budget for your discretionary fund, remove some money for emergency, Bitcoin accumulation, miscellaneous for your planned vacation, family treat or buying that gadget. The percentage that you decide to allocate should depend on their priority to you. The point is that your life shouldn't revolve around basic expenses and Bitcoin alone, although you can choose to allocate more percentage of your income into them, it's your money and your choice.
Living in a country where live is generally tough for an average citizen, I can understand how tough it is to invest in bitcoin and crypto generally. The standard of living has changed significantly for the average citizen making life more unaffordable and finances more difficult to keep. Being able to apportion funds into discretionary funds, emergency, family treats, vacation, buying gadgets or even spare money for miscellaneous is usually almost impossible. The best most of us can do is to sacrifice 60% to bitcoin investment (which is roughly $50) monthly, then the remaining 40% will be for upkeep for the rest of the month (which is around $30). Now imagine living with 30 dollars in a whole month for upkeep, where just buying fuel is averagely 90 cents per litres, fuel alone is more than enough to take the remaining funds for upkeep. This is when you're even earning above the minimum wage which is less than 55 dollars monthly. Now you begin to ask, how many people do really earn above the minimum wage in an unstable economic environment like this?
This is usually the challenge most of us living developing African and Asian countries in the world are facing. It is not our fault that the economy of the country is hurting, forming among the reasons why many of us choose to diversify and invest in bitcoin which although can be volatile, but has more value than our local currencies. This is again the reason why the DCA approach is always the best advice you can preach to us, as much as yoy Want to benefit the majority of the population. DCAing is more realistic to an average person here than the lump sum investments because for many of us, we may never have the opportunity to venture into lump sum investments in our journey to grow our portfolio unless if you’re fortunate enough to be around the elites, driving the economy.