Many altcoins you are seeing right now are build on "Make the project, promise the entire world rare utilities and never really deliver anything, they will keep using words and investors will keep hoping.
The main reason is the proof that most of the altcoins are shit coins. Whatever their concepts and promises, they will be shit coins and not worthy. They have very big promises, but they will not be able to reach them, or even if they reach them, they can only maintain them for a while, and then, fall down tot he earth and become shit coins again.
Only very few altcoins that are exactly surviving around the years, from year to year. Even top coins like Litecoin and XRP which are old coins, are also dropping and cannot reach their previous price again in the last bullish era. Altcoins will likely be always replaced by others in every era.