As of today, if we assume that bitcoin is going down zero for whatever reason then I am 100% sure that it will be the end of altcoins too because they are depend on bitcoin and any movement on the price has immediate effect so if it comes cease to exist then it will be the same for dependants too but in the next 5 or 10 years things might have change and who knows there will be some coin that can overtake the bitcoin in terms of adoption.
Indeed, we must took that cryptocurrency is now dominated by Bitcoin as a leading virtual currency. Bitcoin’s price defines or influences almost every other altcoin in some or the other manner. If Bitcoin collapses to zero, it will wipe out the confidence of the market in all other digital tokens and is the largest financial calamity to have ever occurred to it, let alone altcoins. It is because, as the original establishment is the market leader in the crypto industry, people associate Bitcoin with reliability. Since most altcoins rely on anticipation and additional technologies built on the blockchain, the widespread largely depends on Bitcoin, and its collapse maybe fatal to the entire market as well.
We cannot rule out such changes that might happen in the future all together. The crypto market is also fluctuating, andBlockchain technology is also evolving. Perhaps there will be other coins that could dethrone Bitcoin as it happens now, but with nicer features if they exist or more effective solutions. Such as coins with lower transaction fees, even better scalability or even stronger institutional backing.