Well, I always say 'promising' is the same as 'potential' everything has it,,, even shitcoins have promise and potential.
Bitcoin and Ethereum are the ONLY coins with utility. As in, real utility to do real things not just NFT and Defi nonsense.
If you want to play with fire,,, play on with altcoins but know that you will get hurt because altcoins are always trash coins.
I wouldn't agree that btc and eth are the only ones that have any utility at all, there are some other coins that have the same amount of profit and utility which is why I disagreed. However, I would agree that those two are the only ones that have anything probable, and that is a bit more important.
Let's assume a situation where you are given SOL and ETH, both have their own networks where other projects could put their projects on, and you have a brand new project, which one would you prefer? Sure, some responded with SOL and put their project there but majority does it on ETH network. This is why even though the statement is wrong, the mindset is not too far off in reality.