Popularity and merit are two completely different things. It waxes and wanes. The masses will adopt anything that is convenient and popular (regardless of whether its really great or not).
Look at the #1 Billboard song right now. "Old Town Road". This is the most popular song. Its "what the masses want". What's it about? "Can't nobody tell me nothin'" "Cheated on my baby" "Cowboy hat from Gucci".. Its teenage defiance, materialism, and "macho" unfaithfulness. What happens to be popular right now might mean something important, but it also might just be garbage as usual. (By the way, at the moment, it is popular for humans to create literal mountains of actual garbage.)
The people who created cryptocurrency said what the point was. Its to give us control over our digital money and remove the intermediaries.
People who know better should strive to make things that are worthwhile more popular.
Look at the example of social researchers creating a line of actors in downtown Las Vegas. The line went to nowhere. But simply by virtue of having several people in it, it seemed popular. So it grew in popularity to become a very long line. That went nowhere. The thing that was popular had no merit because it did not exist.
Or look at Juicero. Very popular with investors to the tune of $120 million.
1) Store of value
2) Unit of account
3) Medium of exchange
It's not really very good at any these 3 things. The scalability significantly hurts #3, but even if you fix it it's super volatile, which are bad for 1 and 2. Not only that, but it's inherently deflationary, which is quite bad in the long term, but I guess that's really a secondary concern.