If you ask me, what is the hardest job? Then perhaps my answer will be the investment profession. It is a truly unique and harsh profession compared to other professions. Especially with Bitcoin and a volatile market like cryptocurrency.
You will see that every area of life (sports, education, business, music, academics...) is a competition for rankings. But investing is completely different, it's not about how much money you make compared to those around you, it's a very unique profession, when what you fight for and win is not with others who join the market that is yourself. Win over yourself.
I think this is where it lies a difference between making investment as your main source of income vis-a-vis making it as a sideline. The problem with people who make it their source of income is its unpredictability.
Yes you're right- its market volatility makes it very unstable and unpredictable. Despite knowing the market and all the relevant information regarding its price movement, there is still no guarantee on your investments if it would make a positive return. On the other hand, those people who view it as a sideline would most likely HODL for long-term and they would cash out when they think that the price is comfortable enough for them to realize on their profits.
Between two gamblers or investors, they are also investing in the same way, just different in the category in which their capital will be used. The other is gambling, where the chances of losing the capital you have are high, that you don't need any research to be done just so you can play and win gambling, that you can get lucky in the jackpot, and that you can also be unlucky in gambling.
Whereas in investment, the chances are high that your ROI will be good if you invest in the right investment, and since your comparison is with bitcoin investors, there is no doubt that our ROI will be good for the future with the capital we will use today.
I agree- both have their fair share of similarities (e.g. the risk of losing your money, unpredictability, etc.) but the very essence is different.
Personally, I would definitely recommend investment over gambling due to the latter's risk that can potentially snowball into a bigger problem in the future.