Long tern profitability is directly related to the industry the coin is made for and whether its a working coin or not.
Every alt coin claims that blockchain is the solution for something, but in most cases its just a stretched and to bold claim.
I recommend to look into alt coins that related to an high-transaction industries like fintech or adtech. in particular the last. Imaging what can be done of crypto payment if google decides to offer blockchain based performance marketing mechanics to their ad-networks with dedicated coins.
so thats my take on this topic.
eggman