Polycarbonate is a very useful plastic for food containers ("cambros") because it's lightweight, durable, and can be transparent. Sure, glass could work but it's a lot more fragile, especially if you were to try to constantly stack/unstack them in a commercial kitchen.
To a lesser extent the same argument could be made for polypropylene deli containers (for food storage and kitchen prep, not as disposable food containers).
I use plastic wrap probably more than I should in the kitchen (when baking) which could obviously be replaced by lids that fit whatever containers I'm putting the plastic wrap on but in some applications I can't imagine plastic wrap being replaced without some special lid (proofing a bread loaf that you want to proof out of the top of the container).
I think that's it though. In general, I agree that single-use plastics (or "re-use for a while and eventually throw out") are unnecessary but if something can be used indefinitely (I've had my cambros for something like 5 years at this point and they still look new) then I don't see it as an unnecessary plastic.