While I agree, altcoins will need to work on the legal side of things if there is an SEC crackdown, I do not think they all will die bcoz of that.

The blockchain tech is perfectly intact and many of them including ETH, SOL, MATIC are being widely used. Govts globally are working on regulations and that will have a good effect on the entire industry.

That said, I do agree some of the small cap coins with no use case will go to zero eventually. But if someone wants to invest their hard earned money, they should be willing to put in 20-30 hours of research work to understand about what they are investing into rather than chasing the latest hype