I think this is a myopic view of critique. A good critic helps potential consumers gauge the likelihood they will or won't enjoy a given work, and offers insights that facilitate a deeper engagement with the material. Of course one's own taste is the final arbiter of enjoyment, and of course every critic's own taste is going to flavor their criticism, but that doesn't mean they must believe their own tastes are superior, or that non-critics should take their views as objective facts, or that the whole enterprise serves no purpose for anyone other than practicing artists.

For example, if I watch a movie and don't understand it I could shrug it off and forget about it and there would be nothing wrong with that. But I could also go read critiques of the film and maybe gain an understanding which makes my interaction with the film more enriching, even if it doesn't necessarily change my overall opinion.

I think it's true that critique can never be as valuable as the work it examines, but art only becomes part of culture when it is discussed by the culture. That is what critics are doing.