I am not talking about PoW specifically but about the new research that Bitcoin opened, including new consensus systems in trustless networks. The community knew how to build distributed systems in trusted networks before Bitcoin.

Yes, there were many designs.

I don't know of anyone who really applied traditional BFT networks into public blockchain architecture, however, until Tendermint.

For example, who spoke or wrote of BFT fault accountability/attribution, and how it pertains to proof-of-stake models, before Tendermint?

There was also the 2011 paper that lamented the lack of good open-source middleware for BFT algos. Tendermint solves that engineering problem as well.