Investment is not like trading or gambling that people see more as something very risky that they should not invest more than they can afford to lose on, investment is completely different. You will see rich people investing big unlike trading and gambling. Many people make it in life through investment and they use high amount of money to make the fortune from investment.
Exactly there shouldn’t be too much emphasis on this phrase “not investing more than what you cannot afford to lose” on investment discussions but it should be “invest what you can afford to hold for a long period of time” this will help keep you away from losses as during investment short term investors are those who usually run into loss because they want to make quick profit from their investments.
Then investing crypto currency is to ways; investing what you can afford to hold for a very long time is only applicable to bitcoin only which has proven that it can grow as adoption rises. Investing what you can afford to lose is for Altcoins because it is not an investment in my perspective but a gamble that can go either way and it’s not something to hold on to for a long term except a project which you have long term conviction about (but it is still a gamble )