I am considering taking a loan to buy btc and eth, is it a good idea? Because btc and eth always go up in long term. They never die. There seems to be a great chance of getting huge profit instead of losing money. A few years ago somebody in this forum asked others the same question and everyone told him not to do that, look at the price now. If that guy did, he would have been rich now. Nowadays the situation is not different, the price will continue to go up. I think people who invest more will earn more profit eventually. What do you think?
No person would let you loan any amount that would be paid in an indefinite time. The example you gave about that guy is just you fantasizing about being rich. Take your time and earn your own money to invest in, it doesn't have to be a huge capital you can always start small.