investing in solana long term sounds fine, but bitcoin is far more promising in the long term, my advice, it would sound wiser if you diversified into two coins, in solana and bitcoin
Diversification is a good strategy to implement. Bitcoin becomes the main investment with more allocations. While the rest of the allocation could go to Solana or a top Altcoin like ETH, that would be better than just placing the allocation on Solana.
Actually there are still many choices of altcoins that have good progress, but that's everyone's preference or according to their own research. own risk.