If Bitcoin is blockchain V1 and Ethereum is blockchain V2 then it is being said that Cardano is blockchain V3. Cardano offers scalability and efficiency that cannot be matched by PoW blockchains. The heavy chain weight, cost of transactions and energy consumption are all barriers when it comes to scalability of PoW based coins. Cardano uses a new PoS algorithm (Ouroboros) which claims to be provably secure, energy efficient and more scalable due to the energy efficiency and low entry costs in order to (mine) stake.
I think that Cardano is going to be huge in the future, it promises to be both, scalable and spendable, there will be a Cardano card that can be loaded with ADA and then spent in local currency.
It is new(ish), it is cheap (300 satoshis on bittrex) and its going to be a revolution in cryptocurrencies and accessibility into cryptocurrencies.