At least in my view, BNB has a great token burning system, use in the Binance launchpool, the discounts it earns on Binance and good use in the Pancake Swap, but SOL is more expanded across the entire DeFi ecosystem, SOL can reach a lot of more users than BNB
To be honest I never think marketcap alone is a meaningful metric to decide whether one token is 'better' than the others, especially when we're talking about the top 10 coins. I think there's a new metric called diluted marketcap now, where aggregators calculate it by counting all tokens as circulating tokens or something along those lines. I think that metric is a bit better as a metric to judge how much growth a token can have.
But yeah, as long as the blockchain is stable I don't think Solana will have any issues maintaining their position on a website like Coingecko. Times move quickly in crypto though.
Yes, definitely Solana can have issues that can send it below other coins/tokens on the Coinmarketcap matric used to determine coin/tokens performances. As we know, No conditions is permanent, and coin ranking is also not permanent, it is completely a fact that many altcoins that had managed to hit the top Ten on the Coinmarketcap ranking, has gone far below their previous positions.
For instances, around 2018, Ripple (XRP coin) managed to overtake Etheruem but was a short leave situation, though Ripple was sue by SEC, a situation that might have caused XRP to dwindled in value due to the prolonged law suit that lasted for over a year and six months.
In a nutshell, besides the number one position on Coinmarketcap ranking, bitcoin has maintained the top position, and no altcoins has maintained it's position without being overtaken at certain periods.