I believe that many altcoins will die off due to week fundamentals, all the weak projects, meme coins and speculative tokens will vanish over time. Bitcoin is more entrenched than any other crypto that's why I believe that it's strength will make sure any crypto that actually survives, must justify its existence
Bitcoin doesn't need to kill other cryptocurrency because they're killing eachother with their greed. The projects are greedy and Instead of using the money they have made from token sales to build up the project, they divert the funds and invest it into area that aren't important to the growth of the project. They're only interested in investing in areas that'll make the project more popular and they're doing this because they want to get more popularity to increase the profits they'll be making when they keep selling the tokens of the project. Bitcoin and other cryptocurrency can exist together without any killing the other but Bitcoin has more longevity.