Maybe... if run locally with full transparency into the prompts (including system etc) and independent benchmarks for the models (i.e. tests on how eager they are about selling me stuff)

But even in this hypothetical world I would still have a hard time teaching an LLM what I find important in a product. Not everything can be captured in easy to compare numbers. "Does the device creak under pressure?", "What's the one weirdly unergonomic thing about it you only notice after weeks of using?"... Stuff like that. Things which are easy to miss even if the model ingests all relevant reviews about the product, because it might not stand out, but might be important for me.