A first world problem. Back in the olden days there were 700c / 27" tubes and 26" tubes. Life was simpler back then and most people were easily pleased with either one or the other.

Today there are a plethora of choices - marginally different sizes, different thicknesses, valve stem lengths etc. Bike shop owners must hate it because there are so many different ones that they never seem to have the exact tube that I want in stock.

Personally, I've become an internet buyer because I can order the exact inner tube configuration that I want. The drawback is I have to inventory my own stock of spares.