I would say:

1. Bitcoin

  • Fungibility, which is, a property of money that Bitcoin does not have.

2. Lightning

  1. An easy and standard way of integrating lightning payments everywhere (games, stores, websites, social media, ...)
  2. Non-custodial wallets were you don't need to worry with channel capacity
Point number 3 is rapidly evolving so it is still too early to know where it is going and what it lacks.