I don't think UNI will surpass BNB at the moment, but UNI has pretty good potential to compete with BNB.
If in the future the uniswap exchange is widely used and its reputation is getting better, it may surpass BNB.
That is, if Uniswap will sustain the interest of traders. This early, one major problem that traders is facing with is the high trading fees. This is the reason why I am hearing other dex platforms to be better over Uni. Now, if UNI will not resolve their fee problems, in time, traders will go to other DEXs with competitive fees. And comparing the number of users in centralized exchanges like BNB, I think it is hard to beat centralized ones because there are a lot of centralized coins to cater with, that you can't find in DEX platforms.
After the massive success of uniswap, many DEX emerges and offers different solutions. Like 1inch is a good decentralized aggregator, even metamask is providing a similar service like them with swapping protocol. But the thing is as long as eth fees problem has not been solved it will not be good for any of these exchanges. Recently I got a token from airdrop and I tried to exchange it through uniswap but it askes for over 100$ gas fees. As long as uniswap keeps its reputation high UNI will show good price action.