1. Binance exchange (BNB) has the highest trading volume and ranks 1st;
2. BNB has a blockchain that is widely used by projects and people for transactions;
3. BNB is in top 5 on coinmarketcap.
Possible reasons on which it could really be possibly that it would be replaced into its top spot.
1. Major exploits on BNB chain
2. Some exchange major issues
3. Regulation Issues
4. New and competitive other exchange
So far Binance is really that good on how they would be marketing out themselves on which they are really that able to retain their position or ranking
for how many years now and it doesnt seem that they would really be out of the game soon. As long CZ does maintain on what he's doing in terms of marketing
or market expansion then it might really took a long time for them to stay.
CZ has also done a good thing and it is proven that until now Binance is still in the top ranking,
but this is crypto anything can happen and we'll see in the future what it will be like.