We can see these days that not all people know cryptocurrencies, if they do perhaps they have heard only about bitcoin, but without owning or having the experience of making any transactions.
Maybe altcoins will become popular within 3 years from now?
Altcoins have long been popular. Many of them serve for their own purposes. They are invested and traded in them. Naturally, Bitcoin has the greatest popularity, however, and Altcoins have their own audience.