Bitcoin managed to stay at the very top for a very long time up until now. It wouldn't surprise me to see it in the near future being the most used cryptocurrency. There will surely be a lot of adjustments before such thing would happen and it is required that bitcoin would be fitted to be used by anyone in the world as it gets more universal than ever. There are even rumors that tells bitcoin would be the single currency declared by the new world order. Still those are just theories so there are no certainties yet. We will see what will happen for real but for now, one thing is for sure, bitcoin will keep on dominating till it becomes legal and recognized all over the world.
I assumed because we are in "altcoin" discussion, it was negating bitcoin and asking the other ones. Like right now ethereum is used a lot, even though centralized exchanges are still insanely high, uniswap is doing a big deal, which is growing as well so maybe one day the biggest exchange with the highest volume could become uniswap? Who knows. Or pancake is doing great and BSC (and BNB because of it) could become huge as well, who knows?
This is why I think it is really good to know that if you remove bitcoin out of question, there are few coins/tokens that could become the biggest. Hell Dot is brand new if you consider it and people use that a lot as well, XRP is an old head that I do not think worths the attention it gets, but it is still used, Doge became a crazy thing because of Elon, but I do not believe it could be the most used one. There are a lot of them that could fight for a title behind bitcoin.