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?
This time is really not sure, but the focus is on how the project's team operates and operates to make the altcoin popular.
That will not make altcoin popular, the most affecting thing to make crypto popular is by marketing or advertising it, just for the example the hype bitcoin got back then is because the publicity by the mainstream media, if crypto could repeat the same thing it will work, otherwise it will ended up in misery.