Huh? Automated trading wasn't the 'system' HFT replaced? HFT is automated trading. HFT replaced humans who operated the specialist booths and the market making

Huh? Automated trading wasn't the 'system' HFT replaced? HFT is automated trading. HFT replaced humans who operated the specialist booths and the market making on NASDAQ. Automated trading in the 80's was still run through people to execute trades.