Solana can be a long term option because of the technology behind it (Proof of history). It solves the high gas fee, no heavy mining costs, High TPS (Transaction per seconds) and transparency. Some of the experts say that solana can be next ETH in next 5 years.
A lot of factors that could affect the growth of ETH in the future, market competition is going stronger, and now we are adopting the new platform. If we saw that the ETH price is at $2k, maybe soon it was that half of it. But of course, ETH will still survive as ERC20 tokens still exist but with the massive growth of BSC projects, we can expect a different trend in the coming days.
Thus, if we aim for a long-term investment, I'd choose BTC and BNB considering the current situation, ETH will be another option.