Filecoin is just another cryptocurrency whose purpose is to safeguard a person's important files into the decentralized cloud. It's as similar as both Storj and Sia. Whenever Filecoin is a good or bad long-term investment, that's up to you to decide. Considering that Filecoin is an old project (5 years since its inception) that made it this far, I think it will last for generations. Many are saying decentralized cloud storage is the future, so maybe there's a chance Filecoin will get all of the attention it deserves someday? As long as you don't put all of your life savings into this cryptocurrency, there should be nothing to worry about. Just my thoughts