I recently used Claude and ChatGPT for exactly one of the examples; comparing different bikes to buy. They could both look up the bike specs and geometry online and tell me what the 1 degree difference in head angle or 5mm difference in reach would feel like to ride. They both did really well.

But I used them only (with cross checks) because I was fairly sure they were giving me unbiased info. As soon as the "discovery" phase of this shopping research becomes polluted with adverts, the product becomes much less useful. The same as "no one trusts online reviews anymore".