A few players using them effectively is different than 30-60% of the market being run by algorithms. Granted I can't read much of the article because it is behind a paywall which seems to be very common on HN.
"Visit a trading floor today and you will hear the hum of servers"
In my experience, the machines doing the actual trades are as close as possible to the exchange, generally inside. What's in the trading floor are the client and ML programs that issue the strategies. That said, I've been away from the industry for a few years and it might have changed.
weak human + machine > machine > strong human
IE. Chess / Go / Dota 2
A better machine is just a tool.
One that someone who's smarter than you is going to use to win at the game of poker.
Hence Kasparov's law. You know, the chess guy.
For now.