Why should i invest in bitcoin or other cryptos ?
If you buy land, each year even if you don't work it you get weeds ... if you dry them you can use them to make a fire ...and in turn that generates energy ...
Meaning: that piece of land is giving you a dividend each year .
Where's my dividend if i invest in crypto ?
We all should be. Why? Simple answer, because each year Bitcoin is assumed to have price increase and also other cryptocurrencies at some point of their existence. Why can't you take that as an answer? Land and cryptos are two different things having two different values, they shouldn't be compared with each other.
Also, not taking an opportunity when you already sees it is like not taking your land dividend when it is already being given. But still, it's your choice. But I promise to send you a message on Earth when we're already in the moon.

It is not even assumed, aside from 2018 every year we have gone up, every single year. I am not saying the same will definitely happen because I may never know what's going to happen with bitcoin in the future (nobody can "know", just assume) but it is obvious that we have done something that helped us so far, which means we should be capable of profiting from it in the future as well.
Why? Simple fact of "we made money from bitcoin before and that means we will continue to do so in the future as well" is not the reason, the reason is that we have gone high enough that we know for a fact that bitcoin has nothing wrong with it, it is still quite profitable and that means we are going to end up profiting from it in the long run as well as long as nothing bad happens. Nobody can guarantee anything but bitcoin is not broken so why would it start losing people money?