Cryptocurrency Networks - What's the Connection?

A crypto currency called cardano has climbed even faster than polkadot. It's up more than a thousand % this year to a recent market value of 68 billion dollars. That means it's worth more than fed x the delivery network. Cardano is based on robust academic research. A lot of thought was put into how you just don't create new greatest thing, but how do you make it scalable, sustainable? How do you ensure that transactions could happen at a high rate? How col they happen cheaply?