Personally, I do not like ideas of "going all in" to investments...
To me, it sounds like gambling and or trading rather than investing.
Even though I get the idea that reserve funds can be saved up in order to have extra cash that goes beyond regular DCA buying to be able to inject into your BTC investment at various points along the way, especially at various dippening points.
You are right but investment is now the only way to be profitable for everyone, trading or gambling without experience is not very profitable, if one invests in Bitcoin now, it is almost certain that he will be in a profitable position within a few months.
Also as per your suggestion if one trades and gambles intelligently then more profit is possible, but most of the wise people can't do these things by following the right rules.