From the marketcap it is more likely for SOL to chase ETH, rather than ETH chasing BTC's marketcap, but apart from that some people trust BTC more as a place where they keep their money than ETH in the crypto market, because it is like the ultimate goal of the investment journey in altcoins.
I've heard some great people in this industry, they play and invest in altcoins then when they have made a big profit from altcoins they will save it in bitcoin and that's how they survive the bad hall and full of altcoin risks, therefore bitcoin will never be passed by any coin, except in the previous few cycles it was beaten by XRP in terms of marketcap.
As long as Solana remains a victim of network outages, it will NEVER replace ETH in market cap. Even if developers improve the chain, it's already late to make a difference. Replacing Ethereum would be no different that replacing Bitcoin. And we all know that's impossible.
What will happen is that both Solana and Ethereum will grow in terms of mainstream adoption (usage) and market price. Bitcoin will always stay on top of Ethereum for obvious reasons. Who cares, right? As long as you're able to make money with either coin, nothing else matters.
