There's no exception with all of them because all altcoins are risky. You can't even be sure with the stablecoins right now due to some of them falling.
That's why someone who's investing in altcoins is not just a random investor but they know where they're putting their money.
And it has been ever like this. OP says altcoins have become a risky investment these days, but the truth is that even during bull markets altcoins are dangerous investments. If an investor picks a scam altcoin, he may lose his entire investment, despite being in green market where the prices of cryptocurrencies in general are rising. Moreover, altcoins which were fristly created with a legit purpose may also fall down during a positive season, if investors lose interest for it for different causes. For that reason, it's always necessary to be very careful with altcoins' investment, regardless of market's conditions.
Yeah, think of it at all times that they're all risky no matter what the project is, the risk is always attached to all of them. More with the bull run, more scam projects are coming out with that because the enthusiasm of all investors is there during that time.
And with those scam projects, they're taking the advantage of that moment because they know that everyone will start to pick and invest those projects that might give them wealth in a short period of time.