Altcoins will not die, there’s a limited supply of bitcoin so for sure bitcoin can’t supply the world and people might start looking for a better and cheaper currency so even if bitcoin reach $100k, altcoins will follow the up trend. You might be talking about the shitcoins right now, of course they have no room for growth and they wont grow because the developer are not serious about that. Always invest on top coins/tokens, the whole cryptomarket will go up again.