You can still find unused EA App (Origin) keys on "grey market" sites like G2A or Eneba. Once purchased, you simply redeem the code in the EA App to begin your download.
For those who find the official servers too empty or difficult to access, the community created the project. download titanfall 1 for pc link
You can find used physical copies on Amazon or eBay. However, these still require an EA account for activation and may still face issues with missing DLC. 2. The Fan-Led Way: R1 Delta You can still find unused EA App (Origin)