Things we consider TJ good for now/here (SoCal) include uncured bacon ends (bits&pieces?), cherry tomatoes, our giant basil plant/potted herbs/potted plants generally, frozen desserts, cheese, good bread, and chocolate. And of course wine.
Growing up I remember getting the sense that TJ's was a place for a more "European" shopping experience. Basically, if your list of "bread, cheese, chocolate" are satisfied by "Wonderbread," cheddar, and Hershey's, it's understandable how you wouldn't see the point. My parents went there for things that are unpopular in the US or for things that didn't taste right in the US "standard versions" if you will: cheese, cured meat (salami, etc), crackers, chocolate, mineral water, desserts/treats. Sometimes we got bread or pre-marinated meat as a treat, and I think the price (or perhaps quality) of milk, eggs, canned goods (esp salmon), nuts, and of course wine was comparable/better than traditional grocery stores. We hardly/never got produce, cereals, frozen meals, juice, chips/snacks there.
So I guess my point is: the prices may not be great in general, but on many products the quality/price is fantastic (i.e. same quality elsewhere would be MUCH pricier). It's a matter of taste/choice/preference if that quality (or specialty) in any given product is worthwhile.