Is convenience stores only selling Coke or Pepsi an American thing?

Because over here in the UK, every shop I've seen that sells soft drinks sells both brands at the same time. Probably alongside a bunch of others.

Then again, the branded coolers seem to be more of a thing in restaurants and takeaways rather than shops.

In my experience living here my entire life it’s _far_ more common for a restaurant/ fast food joint to have exclusive deals with one or the other.

That being said there is one popular gas station chain around here that historically sold Coke and Pepsi products in their fountains but in the past decade or so they’ve switched to exclusively Coke products in the fountains (but they still sell bottled Pepsi products)