When I first got into bitcoin in late 2013, I was not really sure about a 1-2 year investment into bitcoin minimum.. but with the passage of time, it seems that the investment case for bitcoin in the long term is even greater, so I doubt that 3-4 years is a long term investment, and if you are planning on cashing out for "sweet gains," then you are surely only thinking in terms of short-term dollar gains rather than planning for a possible lifetime in which you might always own bitcoin absent some kind of notice that you might not be living very long and then decide to cash out  more of your bitcoin within that kind of a context.

Sure one of the problems with older people who might be 65 years or beyond, they might start to feel that they are not really able to sacrifice a lot of liquidity, so they might be worried about their abilities to invest in the long term, and surely a person who is younger with health conditions might have similar difficulties in terms of his/her investment time horizon.    No one can tell you what is your investment time horizon, or what you believe might be a better investment than bitcoin to put your "sweet gains" rather than merely letting your bitcoin investment ride and letting the gains roll over into the potential of more gains when your BTC investment compounds and compounds and compounds.. and yeah, there are no guarantees, and probably the lack of guarantees causes you to feel that there might be some advantage to realize your supposed "sweet gains" rather than merely allowing them to roll over until you reach a higher stage of actually knowing what might be the reason that many longer term bitcoin holders have way more wealth related options as compared to those who are not able to hold through even a whole cycle.