If you take a look at the altcoin exchanges that were the biggest exchanges 2 years ago,
you will see that nearly all of them have lost popularity.
If another competitor manages to gain the top position, BNB might
not be the best investment.
There is a major difference though. If we look at all the altcoin exchanges of the past that went from nothing to something and back to nothing, they inherently have proven to destroy themselves at some point. If your inner core represents a shitcoin exchange, you will never be able to run a professional and compliant exchange properly. Binance is the difference here since it has never been a shitcoin exchange by start. It has been operated in a very consistent manner that keeps pleasing people, even during high volume usage.
As long as Binance manages to keep that up and don't make the same mistake as Poloniex and Bittrex, they will be able to grow further.
The only thing that will be able to somewhat damage Binance is faul play from OKEx and Huobi with their *likely* high positioned government officials in their board.