All things considered, vaccination and the human body are a lot more variable than I think folks possibly understand. It takes people years to even come close to understanding how this stuff works with the human body. The long story short of it is the bivalent booster is still very good to get, and still very effective overall; it's just that it's not *quite* as good at preventing initial infection of the disease. However, it's fantastic at preventing hospitalization and severe disease--which is ultimately what we want.
Either way, I wouldn't take this number on face value and say it "doesn't work" as the person stated posting the article, but just that in one particular way it doesn't work as well.
This still doesn't mean it's useless, and it still doesn't mean you shouldn't get it. You absolutely should get this vaccine. Not the least of which because it can significantly cut down on variants developing, substantially impacts the distribution of the virus. Making people less sick for a day means less chance of viral spread--especially in folks who can't get time off of work and have to work sick (because of course we require this in the US).
A room full of vaccinated individuals is going to fair much better than a room full of unvaccinated folks if someone walks in with covid, that's for damn sure.