Defi history questions. Why MakerDao is called the first defi, not pre-Ethereum dexs?

Two questions on Defi history.

1. There have been decentralized exchanges before Ethereum. Ripple, Counterparty, Bitshare, etc. But they are not called the first defi project. The title seems to go to MakerDao usually. Is this just an Ethereum-centric view of the history? Or because they failed to lead to a thriving Defi ecosystem? If the latter, what were the problems and limitations?
2. Many people call MakerDao the first Defi project. Is this is thanks to OasisDex or Dai stablecoin? OasisDex was started in 2016 as a dex protocol in Ethereum. MakerDao was started (not sure as a real or a test version) in 2015 with a stablecoin called eDollar, but it seems like the real launch was in 2017 with Dai. Time-wise, it is in the order of eDollar – Oasis – Dai. Which one gave MakerDao the recognition of being the first defi?