With my (admittedly limited) understanding of the topic, extracting the water from ocean water is a relatively simple process.

The problem is what do you do with the brine afterwards. The process featured in the article makes it harder for the brine to clog the system, which is admittedly an important step. But you can’t put the brine back into the ocean without risking killing local wildlife.

And I’m not under the impression that there are any practical uses for brine, at least not at that scale.