Actually, there are altcoins which we all should consider to be already dead, in my opinion. If a coin does not comply with a min of use or utility it will end up dead. Also, scam coins end up abadoned, it is just matter of time.
I'd dare to say if any altcoin has a price graph like this one, could be suspected to be dead.
Yes, I think it could just be a temporary dip that will be followed by a recovery. In addition, it is important to distinguish between the different types of altcoins, as their prospects can vary widely depending on the use case, development team, and community support.
On the other hand, some altcoins may be poorly positioned to weather a market downturn or to attract continued interest from investors and users. Factors that can affect the prospects for these coins include cryptocurrency competition, other factors, regulatory challenges or technical issues.
The outlook for ETH, ADA, XRP, TRON, and other altcoins will depend on a variety of factors, including market sentiment, use cases and adoption rates, development progress, community support, and regulatory factors.