It's true. Even though Binance bought CMC it doesn't mean that it isn't fair that Binance is top 1. Even if they didn't bought CMC binance will still take the seat. Like you said, Binance has a great reputation overall. And one of the golden coins. So there's no doubt that binance will dominate the chart.
I don't think Binance needs to buy CMC to get first place there, because indeed they have become the trust of the Traders at this time. What the Binance Team needs to do is they have to stay like this, maintain their good reputation forever so I'm sure their Exchange will remain No. 1 in Crypto world.
Binance has been tested for so long time, and I don't think traders will turn their backs on them. They'll still remain a strong part of people's hearts.