Before you invest or ask someone, ask yourself what kind of tech Cardano already have which other cryptos don't? If Cardano don't have any tech or most of it tech just copy from other then it is a scam. If Cardano have it own tech which do work and standout then invest in it.
Never ever invest in any cryptos which drags on more than a couple years with no tech, example is Lisk. Chance it will never have any tech, forever, at best it will copy from someone down the long road.