Investing in top altcoins has lesser risks than most new altcoins, look what's happening presently, many new projects are now turning into DeFi just to take advantage of the HYPE, if I am holding any crypto project that isn't DeFi from scratch I will dump for another altcoin
You're right that investing in top and trustworthy altcoins has less risk than investing in new altcoins. However, investing in new altcoins has more potential to manyfold your capital than investing in those coins that already been trusted. That's just a common thing that is easy to understand, the more risks, the more profits. Besides, it's true that many projects are following the hype, though, be careful about the hype!