Regardless of any digital currency, it does not have any value itself. Its value comes from whether there is a market and whether it can be used in circulation. If it does not have these two points, it will not have much value. If there is a digital currency that can be used in a specific way If it becomes a currency in circulation, its value will be very high. Do you guys have any recommendations for this type of currency?
You are looking for a solid alternative of investment inside crypto industry, and in my opinion the safest alternative is always Bitcoin. Although it can't be used in a specific way, it's the original cryptocurrency among all, which drives crypto market, launches new bull and bear seasons and has thousands of other cryptos following its lead.
If you still want to look for altcoins, I think the best to do is to look which altcoins offer long term benefits to holders. It can be a native token from a business or company, working like an asset, generating extra income for you. Better yet if such benefits are paid in BTC or stablecoin and dollar.