Warren Buffett, no doubt a very well known character within the financial and investment world, must have many truths that have worked for him, but that does not mean they are absolute for everyone.
He (possibly) doesn't know much about cryptomonies makes him think that he has no future, or probably because his training and experience is more traditional, he doesn't see this type of financial movement very well...however, it is a reality for many of us. He has his own vision about it that doesn't have to be the truth of us.

Invest in businesses or projects you understand and believe in.

This that you mention is very important, really, it is absurd to want to enter in an area that is not known, the failure, starting from the ignorance could come and neither we realize it...

And to see the projects in the long term, this is important, to know that everything has its cycle, not to see only the closest thing, in part this short term vision is what makes many projects disappear.

Very good contribution @ritxi
Thank you.